What is the heat index and how does it affect our perception of temperature. How can you protect yourself from heat-related illnesses. What are the symptoms and treatments for heat exhaustion and heatstroke. How does humidity impact apparent temperature.

What is the Heat Index and Why is it Important?

The heat index, also known as the “apparent temperature,” is a crucial measure that combines air temperature and relative humidity to determine how hot it actually feels to the human body. This metric is essential for understanding the potential risks associated with extreme heat conditions.

Why does the heat index matter? It provides a more accurate representation of how our bodies experience temperature, which can be significantly different from the reading on a standard thermometer. For example:

• An air temperature of 85°F (29°C) with zero humidity feels like 78°F (26°C)
• The same 85°F (29°C) with 80% humidity feels like 97°F (36°C)

This discrepancy highlights the importance of considering humidity when assessing heat-related risks. High humidity impairs the body’s ability to cool itself through sweat evaporation, potentially leading to dangerous situations even at seemingly moderate temperatures.

How Does Humidity Affect Perceived Temperature?

Humidity plays a significant role in how we perceive temperature. When the air is saturated with moisture, our sweat doesn’t evaporate as efficiently, hindering the body’s natural cooling process. This phenomenon explains why a humid day feels much hotter than a dry day at the same air temperature.

The relationship between humidity and perceived temperature is not linear. As humidity increases, its impact on apparent temperature becomes more pronounced. This is why meteorologists and health officials pay close attention to both temperature and humidity levels when issuing heat advisories.

The Science Behind Humidity and Temperature Perception

Our bodies rely on evaporative cooling to maintain a stable internal temperature. When we sweat, the evaporation of moisture from our skin removes heat from our bodies. However, high humidity levels slow down this evaporation process, making it harder for our bodies to cool off.

This interaction between humidity and temperature perception is why tropical climates can feel oppressively hot even when temperatures are not extremely high. The high moisture content in the air creates a “sticky” feeling and can make even moderate temperatures feel uncomfortable.

Understanding the Dangers of Extreme Heat

Extreme heat poses significant health risks, particularly when combined with high humidity. The human body maintains a normal core temperature between 97°F and 99°F (36.1°C to 37.2°C), with an average of 98.6°F (37°C). Exposure to high environmental temperatures can disrupt this delicate balance, leading to various heat-related illnesses.

At what temperatures do heat-related illnesses become a concern? Here’s a breakdown:

• 90°F to 105°F (32°C to 40°C): Risk of heat cramps and exhaustion
• 105°F to 130°F (40°C to 54°C): Increased likelihood of heat exhaustion
• Above 130°F (54°C): High risk of heatstroke

It’s crucial to note that these temperature ranges are general guidelines. Factors such as humidity, individual health conditions, and activity levels can significantly impact how the body responds to heat.

Recognizing Heat-Related Illnesses: Symptoms and Signs

Heat-related illnesses encompass a spectrum of conditions, ranging from mild heat cramps to life-threatening heatstroke. Recognizing the symptoms of these conditions is crucial for prompt intervention and treatment.

Heat Exhaustion: What to Look For

Heat exhaustion is a serious condition that can occur when the body overheats. Common symptoms include:

• Heavy sweating
• Fatigue or exhaustion
• Dizziness or lightheadedness
• Fainting or feeling dizzy upon standing
• Weak but rapid pulse
• Nausea and vomiting

If you or someone around you experiences these symptoms, it’s essential to take immediate action to cool down and seek medical attention if symptoms persist or worsen.

Heatstroke: A Medical Emergency

Heatstroke is the most severe form of heat-related illness and requires immediate medical intervention. Symptoms of heatstroke include:

• Hot, red skin that feels warm to the touch
• Strong and rapid pulse
• Loss of consciousness
• Internal body temperature exceeding 103°F (39°C)

Heatstroke is a life-threatening condition. If you suspect someone is experiencing heatstroke, call emergency services immediately while taking steps to cool the person down.

Treating Heat-Related Illnesses: First Aid and Medical Interventions

Prompt action is crucial when dealing with heat-related illnesses. The appropriate treatment depends on the severity of the condition.

First Aid for Heat Exhaustion

If someone is showing signs of heat exhaustion, follow these steps:

1. Move the person to a cooler environment, preferably air-conditioned.
2. Loosen or remove excess clothing.
3. Apply cool, damp cloths to the body or have the person take a cool bath.
4. Provide small sips of water or sports drinks containing electrolytes.
5. Fan the person to promote evaporative cooling.

Monitor the person’s condition closely. If symptoms worsen or persist for more than an hour, seek medical attention.

Emergency Response to Heatstroke

Heatstroke is a medical emergency requiring immediate action:

1. Call emergency services immediately.
2. Move the person to a cooler environment.
3. Remove excess clothing.
4. Cool the person rapidly using whatever methods available (e.g., cool bath, ice packs, garden hose).
5. Do not give fluids to drink.

Medical professionals will provide further treatment, which may include intravenous fluids, cooling blankets, or ice baths.

Preventing Heat-Related Illnesses: Strategies for Staying Safe

Prevention is the best approach to dealing with heat-related illnesses. By taking proactive measures, you can significantly reduce your risk of experiencing heat exhaustion or heatstroke.

Hydration: The First Line of Defense

Proper hydration is crucial for maintaining your body’s ability to regulate temperature. How can you ensure you’re staying adequately hydrated?

• Drink water regularly, even if you don’t feel thirsty.
• Monitor your urine color – it should be light-colored or clear.
• Avoid alcohol and excessive caffeine, which can contribute to dehydration.
• Consume electrolyte-rich beverages if you’re sweating heavily or engaging in prolonged physical activity.

Remember, thirst is not always a reliable indicator of hydration status, especially in hot conditions or during physical exertion.

Dressing for the Heat: Choosing the Right Clothing

Your choice of clothing can significantly impact your body’s ability to cope with heat. What should you wear in hot weather?

• Opt for loose-fitting, lightweight, and light-colored clothing.
• Choose breathable fabrics that allow sweat to evaporate.
• Wear a wide-brimmed hat to protect your face and neck from direct sunlight.
• Consider UV-protective clothing for extended outdoor activities.

Be prepared to adjust your clothing as needed. If you feel yourself getting too warm, don’t hesitate to remove layers or change into cooler attire.

Environmental Strategies for Heat Management

Managing your environment is crucial for staying safe in extreme heat. What steps can you take to create a cooler living space and reduce your exposure to high temperatures?

Creating a Cool Indoor Environment

When temperatures soar, your home should be a refuge from the heat. Here are some strategies to keep your indoor environment cool:

• Use air conditioning or fans to circulate air and reduce humidity.
• Close blinds or curtains during the hottest parts of the day to block out sunlight.
• Use heat-generating appliances (e.g., ovens, dryers) during cooler evening hours.
• Consider using dehumidifiers in particularly humid climates.

If you don’t have access to air conditioning, consider spending time in public spaces that do, such as libraries, shopping malls, or community centers.

Outdoor Safety in High Heat

When venturing outdoors during hot weather, take precautions to minimize your risk:

• Plan outdoor activities for cooler times of day, typically early morning or evening.
• Seek shade whenever possible, especially during peak sun hours (10 am to 4 pm).
• Take frequent breaks in cool areas if you must be outside during hot periods.
• Use sunscreen to protect your skin from UV radiation, which can exacerbate heat effects.

Be particularly cautious when engaging in physical activities outdoors. Listen to your body and stop if you feel overheated or unwell.

Special Considerations for High-Risk Groups

Certain populations are more vulnerable to heat-related illnesses and require extra precautions. Who is at higher risk, and what additional measures should they take?

Elderly and Young Children

The elderly and young children are particularly susceptible to heat-related illnesses due to their bodies’ reduced ability to regulate temperature. For these groups:

• Ensure they stay in air-conditioned environments during extreme heat.
• Check on elderly neighbors or relatives regularly during heatwaves.
• Never leave children or pets in parked vehicles, even for short periods.
• Encourage frequent hydration and cooler, lighter meals.

Individuals with Chronic Health Conditions

People with certain health conditions, such as heart disease, obesity, or diabetes, may be more vulnerable to heat stress. If you have a chronic health condition:

• Consult your healthcare provider about specific precautions you should take in hot weather.
• Be aware that some medications can affect your body’s ability to regulate temperature or increase sun sensitivity.
• Monitor your condition closely and seek medical attention if you experience any unusual symptoms.

Understanding your individual risk factors and taking appropriate precautions can significantly reduce your vulnerability to heat-related illnesses.

The Impact of Climate Change on Heat-Related Health Risks

As global temperatures continue to rise due to climate change, the frequency and intensity of extreme heat events are expected to increase. How might this affect public health, and what measures are being considered to address these challenges?

Projecting Future Heat-Related Health Risks

Climate models suggest that many regions will experience more frequent and severe heatwaves in the coming decades. This trend could lead to:

• Increased rates of heat-related illnesses and deaths, particularly in urban areas.
• Greater strain on healthcare systems during extreme heat events.
• Exacerbation of existing health disparities, as vulnerable populations may have less access to cooling resources.

Understanding these projections is crucial for developing effective long-term strategies to protect public health.

Adapting to a Warmer World: Public Health Strategies

To address the growing threat of extreme heat, public health officials and urban planners are exploring various adaptation strategies:

• Implementing early warning systems for heatwaves.
• Designing buildings and urban spaces to mitigate heat island effects.
• Expanding access to cooling centers in vulnerable communities.
• Developing heat-resistant infrastructure and transportation systems.

These efforts aim to build resilience against the health impacts of rising temperatures and ensure that communities are better prepared to cope with extreme heat events.

Hot and Cold: Extreme Temperature Safety

Hot and Cold: Extreme Temperature Safety

• Health Conditions
  • Featured
    • Breast Cancer
    • IBD
    • Migraine
    • Multiple Sclerosis (MS)
    • Rheumatoid Arthritis
    • Type 2 Diabetes
  • Articles
    • Acid Reflux
    • ADHD
    • Allergies
    • Alzheimer’s & Dementia
    • Bipolar Disorder
    • Cancer
    • Crohn’s Disease
    • Chronic Pain
    • Cold & Flu
    • COPD
    • Depression
    • Fibromyalgia
    • Heart Disease
    • High Cholesterol
    • HIV
    • Hypertension
    • IPF
    • Osteoarthritis
    • Psoriasis
    • Skin Disorders and Care
    • STDs
• Discover
  • Wellness Topics
    • Nutrition
    • Fitness
    • Skin Care
    • Sexual Health
    • Women’s Health
    • Mental Well-Being
    • Sleep
  • Product Reviews
    • Vitamins & Supplements
    • Sleep
    • Mental Health
    • Nutrition
    • At-Home Testing
    • CBD
    • Men’s Health
  • Original Series
    • Fresh Food Fast
    • Diagnosis Diaries
    • You’re Not Alone
    • Present Tense
  • Video Series
    • Youth in Focus
    • Healthy Harvest
    • No More Silence
    • Future of Health
• Plan
  • Health Challenges
    • Mindful Eating
    • Sugar Savvy
    • Move Your Body
    • Gut Health
    • Mood Foods
    • Align Your Spine
  • Find Care
    • Primary Care
    • Mental Health
    • OB-GYN
    • Dermatologists
    • Neurologists
    • Cardiologists
    • Orthopedists
  • Lifestyle Quizzes
    • Weight Management
    • Am I Depressed? A Quiz for Teens
    • Are You a Workaholic?
    • How Well Do You Sleep?
  • Tools & Resources
    • Health News
    • Find a Diet
    • Find Healthy Snacks
    • Drugs A-Z
    • Health A-Z
• Connect
  • • Breast Cancer
    • Inflammatory Bowel Disease
    • Psoriatic Arthritis
    • Migraine
    • Multiple Sclerosis
    • Psoriasis

Medically reviewed by Elaine K. Luo, M.D. — By The Healthline Editorial Team — Updated on September 17, 2018

Overview

If you’re planning to travel outdoors, be prepared to deal with all sorts of weather. This might mean extremely rainy days or extremely dry days, and from the hottest daytime hours to the coldest nights.

The human body has a normal core temperature between 97˚F and 99˚F, but on average, a normal body temperature is 98.6˚F (37˚C). To maintain this temperature without the help of warming or cooling devices, the surrounding environment needs to be at about 82˚F (28˚C). Clothes aren’t just for looks — they’re necessary to keep warm. You can usually bundle up in more layers during colder months, and you can use fans or air conditioners in warmer months to maintain a healthy core temperature.

In some cases, you may find yourself in an environment with extreme temperatures. It’s crucial to know what health concerns you may face as well as how to avoid any temperature-related health problems.

First, note that the temperature reading on a thermometer is not necessarily the temperature that you should be concerned about. The relative humidity in your environment can affect the temperature you actually feel, which is called the “apparent temperature.” Some example scenarios include:

• If the air temperature reads 85˚F (29˚C), but there’s zero humidity, the temperature will actually feel like it’s 78˚F (26 ˚C).
• If the air temperature reads 85˚F (29˚C), with 80 percent humidity, it will actually feel like 97˚F (36˚C).

High environmental temperatures can be dangerous to your body. In the range of 90˚ and 105˚F (32˚ and 40˚C), you can experience heat cramps and exhaustion. Between 105˚ and 130˚F (40˚ and 54˚C), heat exhaustion is more likely. You should limit your activities at this range. An environmental temperature over 130˚F (54˚C) often leads to heatstroke.

Other heat-related illnesses include:

• heat exhaustion
• heatstroke
• muscle cramps
• heat swelling
• fainting

Symptoms

Symptoms of heat-related illness depend on the type and the severity of the illness.

Some common symptoms of heat exhaustion include:

• sweating heavily
• exhaustion or fatigue
• dizziness or lightheadedness
• blacking out or feeling dizzy when standing up
• weak but fast pulse
• feelings of nausea
• vomiting

Symptoms of heatstroke include:

• reddish skin that feels hot to the touch
• strong and fast pulse
• losing consciousness
• internal body temperature over 103˚F (39˚C)

Treatment

If someone loses consciousness and shows one or more of the symptoms of heat exhaustion or heat stroke, call 911 right away.

To treat heat exhaustion, try to keep yourself cool with cold, damp cloths around your body and slowly take small sips of water until the symptoms begin to fade. Try to get out of the heat. Find some place with air conditioning or a lower temperature (especially out of direct sunlight). Rest on a couch or bed.

To treat heatstroke, cover yourself with cold, damp cloths or take a cold bath to normalize your body temperature. Get out of the heat immediately to a place with a lower temperature. Don’t drink anything until you (or the person experiencing heatstroke) receive medical attention.

Prevention

Stay well-hydrated to best avoid heat-related illness. Drink enough fluids so that your urine is light-colored or clear. Don’t rely solely on thirst as a guide to how much liquid you should be drinking. When you lose a lot of fluids or sweat profusely, be sure to replace electrolytes as well.

Wear clothing that is appropriate to your environment. Clothes that are too thick or too warm can quickly cause you to become overheated. If you feel yourself getting too hot, loosen your clothing or remove excess clothing until you feel cool enough. Wear sunscreen when possible to avoid sunburn, which makes it harder for your body to get rid of excess heat.

Try to avoid places that can get extremely hot, such as inside cars. Never leave another person, child, or pet, even for short periods of time.

Risk factors

Common risk factors that can cause you to be more susceptible to heat-related illness include:

• being younger than 4 or older than 65
• exposure to abrupt weather changes from cold to hot
• being overweight or obese
• taking medications such as diuretics and antihistamines
• using illicit drugs such as cocaine
• exposure to a high heat index (measurement of both heat and humidity)

As with high temperatures, don’t rely solely on the thermometer reading of environmental air for gauging cold temperatures. The speed of the wind and external body moisture can cause a chill that dramatically changes your body’s rate of cooling and how you feel. In extremely cold weather, especially with a high wind chill factor, you can quickly experience the onset of hypothermia. Falling into cold water can also result in immersion hypothermia.

Some cold-related illnesses include:

• hypothermia
• frostbite
• trench foot (or “immersion foot”)
• chilblains
• Raynaud’s phenomenon
• cold-induced hives

In addition to these illnesses, winter weather can cause major inconveniences for travelers. Always be prepared to deal with heavy snow and extreme cold, whether you’re on the road or at home.

Symptoms

When your body first drops below 98.6˚F (37˚C), you may experience:

• shivering
• an increased heart rate
• a slight decrease in coordination
• an increased urge to urinate

When your body temperature is between 91.4˚ and 85.2˚F (33˚ and 30˚C), you’ll:

• decrease or stop shivering
• fall into a stupor
• feel drowsy
• be unable to walk
• experience quick alternations between rapid heart rate and breathing too slowly
• shallow breathing

Between 85.2˚ and 71.6˚F (30˚C and 22˚C), you’ll experience:

• minimal breathing
• poor to no reflexes
• inability to move or respond to stimuli
• low blood pressure
• possibly coma

A body temperature below 71.6˚F (22˚C) can result in muscles becoming rigid, blood pressure becoming extremely low or even absent, heart and breathing rates decreasing, and it can ultimately lead to death.

Treatment

If someone passes out, shows multiple symptoms listed above, and has a body temperature of 95˚F (35˚C) or lower, call 911 immediately. Perform CPR if the person isn’t breathing or doesn’t have a pulse.

To treat hypothermia, get out of the cold as soon as possible and to a warmer environment. Remove any damp or wet clothing and start warming up the middle areas of your body, including your head, neck, and chest, with a heating pad or against the skin of someone with a normal body temperature. Drink something warm to gradually increase your body temperature, but don’t have anything alcoholic.

Even after you begin to feel warm again, stay dry and keep yourself wrapped up in a warm blanket. Seek medical help right away to minimize the harm to your body.

To treat frostbite, soak the affected area in warm water no hotter than 105˚F (40˚C) and wrap it in gauze. Keep any toes or fingers affected by frostbite separated from each other to avoid rubbing the areas against each other. Do not rub, use, or walk on frostbitten skin, as this can cause tissue damage. See your doctor if you still can’t feel anything on your frostbitten skin after 30 minutes.

Prevention

It’s essential to protect anyone experiencing early symptoms of hypothermia. If possible, remove them from the cold immediately. Don’t try to warm a person suffering from serious hypothermia with vigorous exercise or rubbing, as this can lead to further problems.

To prevent cold-related illness, take one or more of these measures when the temperature starts to drop:

• eat substantial meals regularly and drink plenty of water
• avoid drinks with alcohol or caffeine
• remain inside near a source of heat
• wear a hat, beanie, or something similar on your head to retain heat and gloves or mittens on your hands
• wear multiple layers of clothing
• use lotion and lip balm to prevent dryness of your skin and lips
• bring extra clothes to change into in case you get damp or wet
• wear sunglasses when it’s snowing or extremely bright outside to avoid snow blindness

Risk factors

Common risk factors for hypothermia and frostbite include:

• being younger than 4 or older than 65
• consuming alcohol, caffeine, or tobacco
• being dehydrated
• exposing skin to extremely cold temperatures, especially when exercising and sweating
• becoming damp or wet in cold temperatures

Last medically reviewed on January 10, 2017

How we reviewed this article:

Healthline has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. We avoid using tertiary references. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.

• Beat the heat weather ready nation campaign. (2014, July 28). Retrieved from 
  nws.noaa.gov/os/heat/index.shtml
• Cold related illnesses. (2016)
  health.mo.gov/living/healthcondiseases/hypothermia/illnesses.php
• Cold weather illness: Recognition, management, and prevention of cold exposure. (2016)
  uiltexas.org/health/info/cold-weather-illness
• Hypothermia. (2012, December 3)
  cdc.gov/disasters/winter/staysafe/hypothermia.html
• Mayo Clinic Staff. (2014, May 16). Heat and exercise: Keeping cool in hot weather
  mayoclinic.org/healthy-living/fitness/in-depth/exercise/art-20048167
• Mayo Clinic Staff. (2014, November 25). Heat exhaustion. Retrieved from
  mayoclinic.org/diseases-conditions/heat-exhaustion/basics/definition/con-20033366
• Tips to prevent cold related illness. (2014, January 25). Retrieved from
  dmhhs.dc.gov/release/tips-prevent-cold-related-illness
• Top ten Red Cross cold weather safety tips. (2015, February 18)
  redcross.org/news/article/Top-Ten-Red-Cross-Cold-Weather-Safety-Tips
• Warning signs and symptoms of heat-related illness. (2011, June 20)
  cdc.gov/extremeheat/warning.html
• Wexler, R. K. (2002, June 1). Evaluation and treatment of heat-related illnesses. American Family Physician, 65(11), 2307-2315
  aafp.org/afp/2002/0601/p2307.html
• Winter weather. (2015, April 23)
  cdc.gov/disasters/winter/index.html

Share this article

Medically reviewed by Elaine K. Luo, M.D. — By The Healthline Editorial Team — Updated on September 17, 2018

Read this next

• How Extremely Cold Weather Can Affect Your Health

  Snow and freezing temperatures have hit the East Coast. Weather like this can put your health at risk in many ways, but you can take steps to protect…

  READ MORE

• Feel Cold All the Time? Here’s Why — and How to Warm Up

  Medically reviewed by Avi Varma, MD, MPH, AAHIVS, FAAFP

  If you always feel cold, you might just have a lower cold tolerance, but a constant cold sensation can also suggest an underlying health concern.

  READ MORE

• Hypothermia

  Medically reviewed by George Krucik, MD, MBA

  Hypothermia is a condition that occurs when your body temperature drops below 95°F. Major complications can result from this drop in temperature…

  READ MORE

• Myth Busters: Does Cold Weather Make You Sick?

  Medically reviewed by Deborah Weatherspoon, Ph.D., MSN

  Does cold weather really make you sick? Learn why cold weather gets a bad rap and what culprits you should really be wary of.

  READ MORE

• What Can I Do About Cold Feet and Hands?

  Medically reviewed by Stacy Sampson, D.O.

  Whether you have cold feet and hands naturally or there’s a cause that you need to remedy, here’s what to know and what you can do about it.

  READ MORE

• What Is Hyperthermia and How Is It Treated?

  Medically reviewed by Stacy Sampson, D.O.

  Hyperthermia occurs when your temperature climbs too high and threatens your health. Here’s why this happens and what you can do to prevent illness.

  READ MORE

• Diagnosing and Treating a Winter Rash

  Medically reviewed by Debra Sullivan, Ph.D., MSN, R.N., CNE, COI

  A winter rash is an area of irritated skin that develops during winter, often due to dry skin. Learn how to treat and prevent winter rashes.

  READ MORE

• Sun Protective Clothing

  Medically reviewed by Laura Marusinec, MD

  Clothing and hats are among the simplest and most effective ways to guard your skin from the sun’s harmful rays. Unlike sunscreen, you won’t have to…

  READ MORE

• Everything You Need to Know About Ice Burn

  An ice burn can develop when your skin is exposed to very cold temperatures. Learn how to prevent and treat it.

  READ MORE

• What are Forever Chemicals in Water, and How Can We Limit Their Impact?

  “Forever chemicals” are present in much of the world’s water supply. Let’s look at what the studies say about their effects, and how you can remove…

  READ MORE

Temperature Danger Zone – What It Means for Food Safety

Last updated on

6/8/2023

The top priority in a commercial kitchen is understanding and enforcing food safety temperatures. Neglecting them can put customers at serious risk of contracting foodborne illnesses. To ensure food safety, foodservice operators and handlers must understand the temperature danger zone and its impacts. We’ll explain the danger zone temperature range, which foods are most at risk, and how to prevent food from lingering at hazardous temperatures.

Shop All Kitchen Thermometers

Click below to learn about the temperature danger zone:

1. Why Is the Danger Zone Important?
2. How Long Food Can Stay in the Danger Zone
3. How to Hold Cold Food
4. How to Hold Hot Food
5. Danger Zone FAQs

What Is the Danger Zone for Food?

The danger zone refers to the temperature range that accelerates bacteria growth in food. According to ServSafe recommendations, food temperatures between 41 and 135 degrees Fahrenheit represent this danger zone (5 and 57 degrees Celsius). Bacteria thrive and multiply most rapidly between temperatures of 70 and 125 degrees Fahrenheit. The longer food sits in the temperature danger zone, the greater the risk that bacteria will grow.

Why Is the Temperature Danger Zone Important?

When foods are allowed to enter the temperature danger zone, bacteria may grow to unhealthy levels and cause the food to spoil. Dangerous bacteria growth like this may occur without any visible signs that the food is unsafe for consumption. Foods may smell and appear normal but could contain harmful amounts of bacteria that will cause foodborne illness.

This is what makes the temp danger zone extremely important. As a food service professional, it’s your responsibility to keep foods out of the danger zone by using approved methods to chill, heat, and store foods.

What Is Time Temperature Abuse?

Time temperature abuse is the act of allowing foods to stay in the temperature danger zone of 41 to 135 degrees Fahrenheit. Along with cross-contamination, time temperature abuse is a common source of foodborne illness, making it a major health code violation. Foods may become time-temperature abused in three ways:

1. Foods are not held or stored at food safe temperatures
2. Food is not cooked or reheated to the temperature required to eliminate possible pathogens
3. Hot food is not cooled properly before being placed in cold storage

What Are TCS Foods?

TCS stands for time/temperature control safety. Foods that require strict time and temperature control are considered TCS foods. Pathogens love TCS foods because they present an ideal environment for germs to grow and spread. Preventing TCS foods from entering the danger zone and becoming time-temperature abused is a critical food safety practice. These are the high-risk TCS foods that should be closely monitored at all times:

• Milk and dairy products
• Meat and poultry
• Fish, shellfish, and crustaceans
• Shell eggs
• Baked potatoes
• Cooked rice, beans, and vegetables
• Tofu, soy protein, or other plant-based meat alternatives
• Sprouts and sprout seeds
• Cut tomatoes, melons, and leafy greens
• Untreated garlic and oil mixtures

How Long Can Food Stay in the Temperature Danger Zone?

ServSafe states that 4 hours is the maximum length of time ready-to-eat foods can stay in the temperature danger zone. After the 4-hour limit, foods are considered spoiled and must be thrown away. Within the 4-hour time limit, foods can be consumed, reheated, or chilled to bring them back to food safe temperatures. Checking temps every 2 hours allows for a greater window to perform any necessary corrective actions.

How to Keep Food Out of the Danger Zone

Kitchen thermometers are the key to keeping foods out of the temp danger zone. By monitoring and recording food temperatures regularly, you can prevent foods from becoming time-temperature abused. This is imperative while prepping, cooking, and holding food on your buffet line or salad bar.

Follow these important tips to ensure you’re making the best use of your kitchen thermometers to keep food safe for consumption. 

• Always use the right type of thermometer for the job.
• Never rely on the temperature display of your equipment alone.
• Place a thermometer inside your refrigerator or freezer as an additional safety measure.
• Keep written records of all temperature checks that include the temp, the time, and the name of the operator.
• Clean and calibrate thermometers often.

As part of your HACCP training, be sure that your staff members know how to perform these temperature logging procedures to keep your menu items out of the danger zone.

Use our downloadable Food Holding Temperature Log!

Download our Food Holding Temperature Log PDF

Back to Top

Food Holding Temperature

Once your food is cooked to the proper internal temperature or chilled to 40 degrees Fahrenheit or below, it’s important to maintain these safe temperatures before serving. There are several instances in which foodservice professionals need to hold food for extended periods. These instances could include holding food in salad bars and buffet lines or transporting food to off-site locations and catering events.

When transporting food, it is recommended you use a food pan carrier or insulated catering bag to ensure your hot or cold foods remain safe for consumption.

Cold Holding Temperature

The cold food holding temperature for TCS foods must be 40 degrees Fahrenheit or below. Here are some tips to properly hold cold foods so they don’t fall into the danger zone:

• Ensure your cold-holding equipment, like cold food tables and cold crocks, keeps foods at 40 degrees Fahrenheit and below.
• Any cold food held without refrigeration is safe for up to 6 hours, starting from the time it was removed from refrigeration at 40 degrees Fahrenheit and below. 
• Check the temperature of cold foods every 2 hours and discard any cold food that reaches a temperature of 70 degrees Fahrenheit or higher.

How Cold Does a Salad Bar or Refrigerator Have to Be to Keep Food Safe?

Salad bars and refrigerators need to maintain temperatures at 40 degrees Fahrenheit and below to prevent the growth of dangerous bacteria. This is especially important as you house vulnerable TCS foods including cheese, yogurts, meats, salad dressings, and egg products.

Hot Holding Temperature

The appropriate holding temperature for hot food is 135 degrees Fahrenheit or above. Here are some tips to keep hot foods out of the danger zone:

• Never use hot holding equipment to reheat food. Foods should be heated to safe temperatures prior to holding. Hot holding equipment, like steam tables and holding cabinets, is designed to maintain current temps, not bring food up to temp.
• When possible, keep food covered to help maintain temperatures and keep contaminants out.
• Stir frequently to distribute heat throughout the food.
• Use the appropriate thermometer to monitor food temperatures often.
• Discard hot food that has been sitting below 135 degrees Fahrenheit for more than 4 hours.
• Never mix freshly prepared food with foods already being held for service to prevent cross-contamination.

How Often Should I Check the Temperature of Hot or Cold Holding Food?

It is recommended you check the temperature of your hot or cold holding food every four hours. However, if you check every 2 hours instead, this allows enough time to take corrective action if food has fallen into the danger zone. By staying on top of your food’s internal temperatures, you can prevent the spread of dangerous bacteria and eliminate food waste by simply re-heating or re-chilling the affected foods before bacteria has time to spread.

Danger Zone FAQs

Here are some of the most common questions about the danger zone that you may encounter in your kitchen:

Proper Cooling of Foods

If you’re preparing food ahead of time and placing it into cold storage for holding, it has to be properly cooled first. Once your menu item has reached its proper internal temperature, it is essential to quickly bring the temperature down through the danger zone. Cool your food to 70 degrees Fahrenheit within 2 hours and then further down to 41 degrees Fahrenheit within 4 hours.

Though it seems like the simplest option, placing hot food directly into your refrigerator or freezer is never recommended because it endangers the food around it by raising the ambient temperature in your fridge or freezer. This creates the possibility of other foods in your refrigerator or freezer entering the temperature danger zone and developing bacteria without you even knowing. Instead, follow these tips for quickly cooling your hot foods.

• Use a commercial blast chiller to cool foods quickly and minimize the time food spends in the danger zone.
• Store foods in shallow containers to allow the temperature to distribute more evenly.
• Consider using a cooling paddle to reduce the temperature of hot liquids including soups, stews, and sauces.
• Create an ice bath by filling a pot, container, or sink basin with ice. Containers of hot foods can be placed in the ice bath to quickly cool food to 40 degrees Fahrenheit or below.

How to Thaw Food

One of the most common examples of time temperature abuse in a kitchen is defrosting food incorrectly. It can be tempting to leave food out on the counter to thaw or run it under hot water, but these put your foods at risk of entering the danger zone. Use the following methods to defrost food safely:

• Move the frozen food to the refrigerator 10-24 hours before cooking.
• Place the frozen food under cold running water in a clean prep sink.
• Use the defrost setting on a microwave.
• Cook from frozen, regularly checking internal temperatures.

Safe Cooking Temperatures

Along with concerns for the danger zone, you’ll also want to make sure your foods have reached safe internal temperatures for at least 15 seconds before they can be served. Below is a temperature guide for some of the most common ingredients.

• Cook to 165 degrees Fahrenheit: Poultry, stuffing, any dish that contains a cooked TCS food
• Cook to 155 degrees Fahrenheit: Ground meat, flavor-injected meats, eggs from the shell
• Cook to 145 degrees Fahrenheit: Seafood, steaks and chops, game meat, roast meats
• Cook to 135 degrees Fahrenheit: Fruits, vegetables, grains, legumes

Back to Top

It’s every food service operator’s top priority to keep the food they’re serving safe for consumption. Following these important tips and getting your staff food handling certified will ensure that they have the knowledge to keep food out of the danger zone, take corrective action, and protect customers from foodborne illnesses.

Burger Temperature Chart

Burgers are a staple of American cuisine, being one of the United State’s most iconic and recognizable foods. One of the best features of burgers is t

Produce Storage Guide for Restaurants

Every chef or restaurateur has experienced the frustration of food spoilage. Knowing how to store produce will reduce food waste, maximize your restau

Preparing for a Health Inspection

Health inspections can be a frustrating and stressful experience, but it’s important to remember that health inspectors don’t come looking to shut dow

• Topics 1239
• Industrial 48
• Troubleshooting Guides 15
• Restaurant Management 123
• Bar Management 52
• Catering Tips 32
• Bakery Management 40
• Food Trucks & Concessions 51
• Advertising & Marketing 38
• Eco-Friendly Tips 10
• Facility Layout & Design 37
• Coffee Shop Tips 27
• Installation & Maintenance 44
• Janitorial & Pest Control 29
• Safety & Sanitation 83
• Startup Tips 101
• Menu Design 10
• Kitchen & Cooking Tips 71
• Hospitality Management 22
• Pizza & Sandwich Shop Tips 35
• Smallwares 34
• Food Prep 76
• Tabletop Items 16
• Disposables 22
• Calculators & Tools 6
• Consumables 42
• Warewashing & Laundry 18
• Cooking Equipment 81
• Food Storage & Refrigeration 41
• Beverage Equipment 29
• Office Supplies 6

• Resource Type

• In-Depth Articles242

• Buying Guides272

• How-Tos95

• Product Reviews68

Temperature as the most important parameter for food safety

How microorganisms can get into food and what accelerates their reproduction

Bacteria enter food mainly:

• through production staff
  ;

• from raw foods
  ;

• from animals or pests;

• by air;

• through poorly washed equipment, inventory, from waste.

In order to live and multiply, microorganisms need:

The food worker cannot control acidity, oxygen supply, or moisture content, but he can control time and temperature.

The influence of temperature on the growth of microflora

The cold chain is a set of measures aimed at maintaining a constant temperature required for a particular product, along the entire path of its movement from production to consumer.

For identical groups of goods, the temperature storage regimes are similar. For example, for dairy products, confectionery and culinary products, this is most often from +2 to +6 С; for chilled offal and poultry – from -2 to +2 С or +4 С. However, for different manufacturers, depending on the ingredients, manufacturing technology and packaging, these parameters may vary slightly.

The temperature of food storage is extremely important, because under favorable conditions, the number of microorganisms will double every 20 minutes. That is, from 1 bacterium in 6 hours it will turn out … 262 144!

Temperature influence:

• at -18 °C – there is no growth in numbers, microorganisms “sleep”;

• from +1 to +5 ° C – most bacteria do not multiply or do it very slowly;

• from +5 to +63 °C – danger zone: rapid population growth; these are the most favorable temperatures for the reproduction of bacteria;

• from +63 to +75 ° C – most microorganisms do not multiply;

• from +75 to +100 °C and above – most microorganisms die.

Thus, keeping food products and ingredients at the right temperature is one of the most important things a food worker can do. After all, if you leave food for a long time at unacceptable temperatures for them, this will create conditions for the growth of microorganisms, sometimes to a dangerous level. In this regard, perishable foods, such as meat, fish, confectionery and dairy products, are at increased risk, but dry foods, such as rice and legumes, can also contain bacteria that will grow if the temperature is not controlled not only during storage, but also during cooking, cooling and heating.

How and with what to measure temperatures

Non-contact thermometers are designed for remote temperature measurement on the surface of an object. They are convenient, for example, to check the temperature in the car body when receiving products.

The probe thermometer measures the temperature of gaseous, liquid, semi-solid and granular substances. They can most accurately measure the temperature of the product inside.

The use of mercury thermometers in food enterprises is prohibited due to high risks.

During cooking, food must reach a certain temperature. How to measure the temperature to ensure the accuracy of the instrument readings? For meat and poultry, insert the probe thermometer into the thickest part for at least 15 seconds. If there is a bone inside, make sure the thermometer is not touching it – the bone may be hotter than the meat surrounding it, and therefore measuring its temperature may not indicate that the edible part has reached the right temperature.

For meats such as hot dogs or hamburgers, insert the probe through the vertical end. For casseroles and other similar dishes, insert the appliance into the center of the dish. It is important to ensure that the appliance does not contaminate food. To do this, it must be thoroughly washed and disinfected.

Over time, thermometers can lose their ability to measure temperature accurately, so they need to be calibrated and verified periodically. Designate a person responsible for this and ensure that valid supporting documents are in place.

Temperature control during receiving, storage and cooling

It is very important to control the temperature of products, especially perishable products, from the moment they are received. This will help determine if the cold chain has been broken during transport.

Frozen food with signs of defrosting and refreezing – ice crystals, frozen liquid, water stains, etc. – should not be accepted

The fact is that when frozen, microorganisms “fall asleep”, their vital activity slows down. When the product is defrosted, they begin to multiply actively. If the goods are refrozen, there will already be more microorganisms in it, and when they are thawed again, their number is likely to become critical.

Perishable food should be stored in the refrigerator at the temperature indicated on the label, usually +6 ºC or colder. Frozen – usually not higher than -18 ° C.

Check and record the temperature in refrigerators and freezers at least once a day. If the equipment cannot keep food at the required temperature, it must be repaired or replaced.

Arrange products in refrigerators and freezers correctly:

• when laying out, it is impossible to block the ventilation grilles, the goods should not interfere with the movement of air flows;

• loading of products into the chamber or showcase should be carried out only after it has reached the required temperature;

• it is necessary to observe the maximum allowable load of the equipment; it is impossible to lay out products above the permissible level;

• when loading products into cold stores, leave enough space for rotation and movement between products. Do not store food in bulk, as this interferes with air circulation and proper cooling.

Temperature control for cooking and reheating

Raw foods, such as meat or vegetables, may initially contain high levels of microorganisms. Therefore, it is important that food is thoroughly cooked to core temperature.
at least 75 °C
.

Optimal storage conditions for certain types of prepared meals and culinary products

• The readiness of meat and poultry is determined by the release of colorless juice at the puncture site and by gray color on the cut of the product, as well as
  temperature in the thick
  . For example, for minced poultry meat, the recommended temperature is not less than 85 ° С , for cutlet mass – is not lower than 90 ° С .

• The readiness of products from minced fish and fish is determined by the formation of a fried crust and easy separation of meat from the bone. Recommended temperature not less than 70 °C .

It is recommended that you keep a record of the checks you have made, especially if the core temperature measurement is a critical control point within the HACCP system.

Temperature control during product storage

Finished products are stored in accordance with the technological map. There are optimal storage conditions for some types of products.

• For example, boiled meat, poultry and offal for the first and second courses are stored in the broth in which they were cooked at a temperature of +75 ° C until the release to the buyer for no more than one hour.

• Salads, vinaigrettes and sliced ​​​​components are stored unseasoned at a temperature of +2 to +6 ° C for no more than six hours.

• Raw minced meat – at a temperature of +2 to +6 ° C for no more than 12 hours.

• Minced meat for filling pies and pancakes is used within two hours after frying.

• Perishable food products after opening the package should be sold within 12 hours, subject to storage conditions.

• Egg powder after swelling for 30-40 minutes is subjected to cooking.

• Creams – custard, whipped cream, cottage cheese – are used immediately after preparation.

• Other types of creams are stored at the factory until they are used at a temperature of +2 to +6 °C for no more than 1.5 hours.

• Freshly prepared confectionery products with cream are stored at a temperature not exceeding +16 °С … +18 °С for no more than two hours. Further in the refrigerator at a temperature from +2 °C to +6 °C during the expiration date.

Hot product cooling

To ensure that food does not remain in the danger area for too long, it must be cooled down as quickly as possible. It is good practice to aim to cool food below 8°C within 90 minutes.

Techniques such as reducing the portion size, spreading food on an open tray or using ice, shock cooling in a special chamber will help with this.

Portioning of chilled and ready-to-eat meals, including cold appetizers and salads, culinary products, is recommended to be carried out in a room with an air temperature not higher than +15 °C or on tables with a cooled work surface.
In the absence of such a room or tables with a refrigerated surface, the portioning process should be carried out for no longer than 30 minutes.

Accounting for measurement results

The results of temperature measurement at any stage must be recorded. Checklists, magazines, and the like can be accepted as forms. Records must contain the date and time of temperature recording, identification
equipment
, FULL NAME. responsible for the entered information and features of corrective actions, if any.

Food defrosting

There are several ways to defrost products.

So, defrosting food in the refrigerator takes at least 24 hours, so this method requires planning ahead. Place the food on the tray in case liquid leaks out of the packaging. Food to be defrosted should be placed on the bottom shelf of the refrigerator.

Defrosting in cold water is faster than in a refrigerator and usually takes several hours depending on the weight of the food. Place the frozen food in a waterproof plastic bag and completely submerge it in cold running water at 21°C or lower. After defrosting, food should be cooked immediately.

To defrost food in the microwave, remove the packaging from the food and place it in a microwave-safe container. Then follow the instructions for defrosting food.

Food can also be thawed while it is being prepared, such as when you make soup from frozen vegetables.

Features of defrosting some products:

• It is not safe to defrost meat in water or on a hot stove. It is best to use a defroster 0. ..+6 °C, microwave or raw meat table.

• Can be thawed in water
  offal
  .

• It is better to defrost fish in the air or
  in cold water
  with a temperature not higher than +12 °C. To reduce the loss of minerals, it is recommended to add salt to the water at the rate of 7-10 g per 1 liter.

• Fish fillet, sturgeon fish are best thawed in the air.

Thawed foods are not re-frozen

Start cooking immediately after defrosting.

What kind of weather is deadly for people?

The summer of 2022, like many previous ones, is very hot. At the end of June, residents of Moscow and other large cities were languishing in the heat – several cool days with rain are expected in July, but abnormally hot weather promises to return again. On such days, many people douse themselves in cool water and say that they are “dying from the heat.” The question arises – but really, at what air temperature does a person risk dying? Scientists have long been trying to figure out the limits of the endurance of the human body and are constantly making new discoveries. Let’s say right away that a person can feel bad after a few tens of minutes of being in the open sun. But there is an even more dangerous condition in which the human body receives the greatest damage.

Sometimes hot summers are more dangerous than freezing winters

Contents

• 1 Why is sun exposure dangerous?
• 2 The healthiest weather
• 3 Which countries are the hottest?
• 4 Which is better, heat or cold?

Why is exposure to the sun dangerous?

Obviously, the greatest harm to a person’s health is caused when he is outdoors. In summer, the air temperature even in the shade can reach 30 degrees Celsius, and in open areas this figure can be 10-20 points higher. Under the sun, the head becomes especially vulnerable – high temperatures heat the cerebral cortex, which leads to vasodilation. Because of this, a large volume of blood flows to the head, which can cause rupture of small vessels. Because of this, the entire central nervous system suffers.

In hot weather, you should never stay outdoors.

In hot weather, you risk suffering from heat stroke or sunstroke. These are two different phenomena - we talked about the differences in this material.

The most dangerous weather for health

But a person can suffer from extreme heat, even if he is in the shade. Bad things can happen if wet bulb conditions are established. The weather is such if the air temperature averages 31.1 degrees Celsius and the relative humidity is 95%. Under such conditions, the human body loses the ability to regulate body temperature through sweating, which is why heat stroke occurs with all the consequences. Experts believe that even perfectly healthy people with great endurance die in such conditions.

High humidity heat is always harder to bear

According to Professor Radley Horton, “wet bulb” conditions are deadly even if the person is wearing light clothing and carrying an unlimited amount of water. No matter how much he sweats, the body temperature will still rise – the only way to escape is to find a cool place with less humidity.

Why do +4 degrees feel cold in autumn and warm in spring? The answer is here.

Which countries are the hottest?

Hot and humid conditions are hardest to escape in South Asia, the coastal regions of the Middle East and southwestern North America. However, dangerous weather can form in other regions such as the US, Canada and even Russia. In the course of scientific work, the results of which were published in the scientific journal Science Advances, the above-mentioned Professor Radley Horton and his colleagues studied data from weather stations around the world collected from 1979 to 2017. They were able to detect about 7,000 occurrences of wet bulb conditions. It is highly likely that hundreds or even thousands of people died due to the heat in such weather.

“Wet bulb” conditions can occur anywhere except, perhaps, the cold parts of the Earth

As a result, it turns out that the summer heat is far from being the most heavenly conditions.