What is the average human body temperature. How does body temperature vary throughout the day. When should you be concerned about your body temperature. What factors can affect normal body temperature readings.

The Myth of 98.6°F as the “Normal” Body Temperature

For many years, 98.6°F (37°C) was considered the standard “normal” body temperature. This belief originated from research conducted by German physician Carl Wunderlich in the mid-1800s. Wunderlich measured the axillary (armpit) temperatures of approximately 25,000 people and arrived at an average of 98.6°F.

However, recent studies have challenged this long-held notion. A comprehensive review of temperature records spanning from 1860 to 2017 revealed a gradual decline in average oral temperature by about 1 degree Fahrenheit, settling at around 97.5°F (36.4°C).

Factors Contributing to Declining Average Body Temperatures

• Lower metabolic rates: Modern lifestyles and increased average body weights may result in lower heat production.
• Reduced infection rates: Historically common infections like tuberculosis and syphilis, which could elevate body temperature, are now less prevalent.
• Improved thermometer accuracy: Contemporary measuring devices provide more precise readings compared to those used in the 19th century.

Understanding the Range of Normal Body Temperature

Contrary to popular belief, there isn’t a single “normal” body temperature. Instead, body temperature can vary within a range of 97°F to 99°F (36.1°C to 37.2°C) and still be considered healthy. This range accounts for individual differences and daily fluctuations.

Daily Temperature Fluctuations

Body temperature typically follows a diurnal pattern, with lower readings in the morning and higher temperatures in the late afternoon or evening. These variations can be as much as 1 to 2 degrees Fahrenheit.

When Does Body Temperature Indicate a Fever?

Despite the evolving understanding of average body temperature, the medical community still defines a fever as a temperature at or above 100.4°F (38°C). However, it’s important to note that you can be ill even with a lower temperature.

Special Considerations for Older Adults

In older individuals, the body’s response to infections can differ from that of younger people. Instead of developing a fever, serious infections in older adults may manifest as confusion or unexplained weight loss. For this demographic, doctors often consider a temperature 2 degrees higher than usual as a potential sign of infection.

The Impact of Medications on Body Temperature Readings

It’s crucial to be aware that certain over-the-counter medications can affect body temperature readings. Common fever reducers such as acetaminophen, aspirin, ibuprofen, and naproxen may mask an elevated temperature if taken for other symptoms like pain.

Proper Techniques for Measuring Body Temperature

Accurate temperature measurement is essential for assessing health status. While various methods exist, some are more reliable than others.

Most Accurate Method: Rectal Thermometers

Rectal thermometers provide the most accurate readings but can be uncomfortable for many individuals. They are often used for infants and young children where precision is crucial.

Recommended Method for Adults: Oral Thermometers

For adults, oral thermometers are generally considered the best balance between accuracy and comfort. To use an oral thermometer effectively:

1. Wash your hands thoroughly with soap and warm water.
2. Avoid eating or drinking for at least 5 minutes before taking your temperature.
3. Place the thermometer tip under your tongue and keep your mouth closed.
4. Wait for the thermometer to beep (usually 30-40 seconds).
5. Read the final temperature and add 0.5 to 1 degree to account for the difference between oral and rectal readings.
6. Clean the thermometer with alcohol and rinse with cold water after use.

Less Accurate Methods

Armpit, ear, and forehead thermometers are convenient but generally less accurate than oral or rectal methods. These can be useful for quick checks but may not provide the precision needed for medical decisions.

When to Seek Medical Attention for Body Temperature Concerns

While slight variations in body temperature are normal, certain situations warrant medical attention.

High Fever Guidelines

• If your temperature is between 100°F and 102°F (37.8°C to 38.9°C), rest and stay hydrated. You may take a fever reducer if desired.
• For temperatures over 102°F (38.9°C) that don’t respond to fever-reducing medication within an hour, contact your healthcare provider.

Other Concerning Symptoms

Seek immediate medical attention if you experience a fever accompanied by:

• Severe headache
• Stiff neck
• Throat swelling
• Confusion

These symptoms may indicate serious conditions such as strep throat or meningitis that require prompt medical intervention.

The Role of Body Temperature in Diagnosing COVID-19

During the ongoing COVID-19 pandemic, body temperature has become an important screening tool. Many individuals infected with the SARS-CoV-2 virus experience fever as a primary symptom, often accompanied by fatigue and a dry cough.

When to Get Tested for COVID-19

If you develop a fever along with respiratory symptoms like cough or shortness of breath, especially if you’ve had potential exposure to someone with COVID-19, contact your healthcare provider for guidance on testing and next steps.

Monitoring Body Temperature for Health Management

While regular temperature checks aren’t necessary for healthy individuals, your doctor may recommend monitoring your temperature in certain situations.

Tracking Temperature Patterns

In some cases, healthcare providers may ask patients to record their temperature at specific times, such as first thing in the morning or at night. This information can help identify patterns or changes that might be relevant to diagnosis or treatment.

Temperature Monitoring in Chronic Conditions

For individuals with certain chronic health conditions, regular temperature monitoring may be part of their ongoing health management. This can help detect early signs of infection or other health changes that require attention.

The Future of Body Temperature Assessment

As our understanding of body temperature continues to evolve, new technologies and approaches to temperature assessment are emerging.

Wearable Technology

Advances in wearable devices are making continuous temperature monitoring more accessible. These devices can track temperature trends over time, potentially providing early warning signs of illness or other health changes.

Artificial Intelligence in Temperature Analysis

Researchers are exploring the use of artificial intelligence to analyze temperature data alongside other health metrics. This could lead to more personalized and accurate interpretations of what constitutes a “normal” or “concerning” temperature for each individual.

Population-Level Temperature Studies

Ongoing research into population-level temperature trends may continue to refine our understanding of average body temperatures and how they’ve changed over time. This could lead to更新された基準temperatures and improved diagnostic criteria for fever-related conditions.

Understanding your body’s normal temperature range and knowing when variations might signal a health concern is an important aspect of personal health management. By staying informed about the latest research and guidelines, you can make more informed decisions about when to seek medical attention and how to interpret your body’s signals.

98.6°F Is No Longer The Rule

Written by Hallie Levine

Medically Reviewed by Dan Brennan, MD on December 24, 2022

• The Myth of 98.6
• How to Take Your Temperature
• When to Call a Doctor

You probably always heard that the average human body temperature is 98.6 F. But the reality is that a “normal” body temperature can fall within a wide range, from 97 F to 99 F. It’s usually lower in the morning and goes up during the day. It peaks in the late afternoon or evening, sometimes by as much as 1 or 2 degrees.

If you’re healthy, you don’t need to take your temperature regularly. But you should check it more often if you feel sick or if you think you might have come into contact with an illness such as COVID-19. Many who are infected by the coronavirus have a fever or a temperature that’s higher than usual. Most also have fatigue and a dry cough.

The 98.6 F standard dates to the mid-1800s. German doctor Carl Wunderlich measured the armpit temperatures of about 25,000 people and came up with an average of 98. 6 F.

Newer research suggests that the number has since gone down. In a recent review, scientists looked at temperature records from three periods between 1860 and 2017. The average oral temperature slowly fell by about 1 degree to 97.5 F. A person’s age, gender, or weight didn’t make a difference, nor did the time of day.

Doctors have several ideas about why body temperatures are falling. They include:

• Lower metabolic rates. Your body uses energy so all your systems can work the way they should. This creates heat. But people may have lower metabolic rates now because we weigh more than people did centuries ago. The less heat your body makes, the lower your temperature.
• Lower rates of infection. In the 19th century, infections such as tuberculosis, syphilis, and long-term gum disease were more common. As a result, many people had higher body temperatures.
• Better thermometers. We may have more accurate thermometers than people did a century ago.

Despite the new research, doctors don’t consider you to have a fever until your temperature is at or above 100.4 F. But you can be sick if it’s lower than that.

Older adults’ bodies don’t respond to illnesses the way younger people’s do. Serious infections tend to cause symptoms such as confusion or weight loss rather than fever in older people. Doctors consider a temperature that’s 2 degrees higher than usual to be a sign of infection.

Also, over-the-counter medicines like acetaminophen, aspirin, ibuprofen, and naproxen are fever reducers. They might hide a high temperature if you take them for another symptom such as pain.

A thermometer is the only way to know that you have a fever. Touch tests and skin pinching aren’t reliable. Rectal thermometers, which go into your rear end, are the most accurate, but they can be uncomfortable. Armpit, ear, and forehead thermometers aren’t as accurate. Most doctors think an oral thermometer — which you hold under your tongue — is best. Don’t use an old glass thermometer. These contain mercury, which is dangerous.

Before you use an oral thermometer, wash your hands with soap and warm water. Don’t eat or drink anything for at least 5 minutes before you take your temperature. Put the tip of the thermometer under your tongue. Keep your mouth closed. After about 30 or 40 seconds, the thermometer will beep. That means the final reading is ready. Oral thermometer temperatures are about 1/2 to 1 degree cooler than rectal ones, so add that much to your reading. When you’re done, rinse the thermometer in cold water, clean it with alcohol, and rinse again.

If you have a child younger than 3, a rectal thermometer may be easier and more accurate. Put a small amount of lubricant like petroleum jelly on its tip. Have your child lie on their belly, and insert the thermometer into their bottom until the tip is completely inside. Don’t force it. When you hear the beep, after about 30 seconds, remove it. Check it and then clean it again.

If your temperature is between 100 and 102, drink plenty of fluids and rest. You can take a fever reducer if you like.

Call your doctor if your temperature is over 102 F and it doesn’t go down within an hour after you take a fever-reducing medication.

If you have a fever with a cough or shortness of breath and think you might have come into contact with someone who has COVID-19, call your doctor to talk about the next steps.

Always call your doctor if you have any kind of fever along with a severe headache, a stiff neck, throat swelling, or confusion. They may be signs of a serious condition, such as strep throat or meningitis.

Even if you don’t have these symptoms, your doctor may tell you to take your temperature at certain times, like first thing in the morning or at night. You can record the readings and report back.

Top Picks

Body Temperature Is 96, But I Feel Sick: Causes and More

Normal body temperatures vary, but if your temperature is 96 and you feel sick, there might be something else going on. It could a sign of sepsis, or something simpler. Only your doctor can tell you for sure.

You may feel ill and take your temperature assuming you have a fever. Instead, your thermometer reads 96°F (35.55°C). This lower-than-average temperature could occur for several reasons. You may have an illness that corresponds to low temperatures. You may have taken your temperature incorrectly. Age may play a factor. Finally, you may have a health condition causing a lower body temperature.

Understanding body temperature is important to making sense of your 96-degree reading. Long ago, doctors considered 98.6°F (37°C) to be a “normal” temperature. That has changed in recent years. A normal temperature is now considered to be a bit lower than that, and it depends on your age and the method you use to measure your temperature.

One 2019 research review looked at 36 prior studies about body temperature and found that adults less than 60 years old had an average temperature of 98.04°F (36. 68°C). Adults more than 60 years old had a average temperature of 97.7°F (36.5°C).

The study also examined body temperatures taken with different methods. These average temperatures by method were:

• Rectal: 98.67°F (37.04°C)
• Eardrum: 97.95°F (36.64°C)
• Oral: 97.83°F (36.57°C)
• Armpit: 96.75°F (35.97°C)

Average temperatures for newborns and children are also different:

• Newborns: 97.7 and 99.5°F (36.5 and 37.5°C).
• Children: 96.8 and 99.5°F (36 and 37.5°C).

Certain illnesses, or incorrect temperature readings, could factor into why your thermometer reads 96°F (35.55°C), but you feel sick. Low body temperature could also be a symptom of a serious illness like hypothermia or sepsis, but you’d likely have severe symptoms.

Incorrect temperature taking

One common reason your thermometer may read 96°F (35. 55°C) is because you took your temperature incorrectly.

• Make sure you are following the manufacturer’s instructions for your thermometer.
• Consider any factors that could have led to an inaccurate temperature. An oral reading may be affected if you’ve sipped a cold drink or kept your mouth open while taking your temperature. An armpit reading may be lower if you did not hold the thermometer in the correct place or if you improperly closed your arm.
• Take your temperature a few times to make sure the reading is correct.

Hypothermia

Hypothermia occurs when your body is at 95°F (35°C) or lower in adults. For children and infants, it can occur when their temperature is lower than a reading in the normal range. Hypothermia is a very serious medical condition that can lead to death if not treated immediately by medical professionals.

This condition can occur because of exposure to cold weather, submersion in cold water, prolonged time in cold and wet clothes, or a cold home environment. An early symptom of hypothermia is shivering.

Hypothermia requires immediate medical attention, so you should call for emergency help if you suspect you have hypothermia. If you have to wait for medical help, try to warm yourself up with blankets or a hot drink.

Sepsis

A drop in body temperature could be a symptom of sepsis. This occurs when your body starts fighting itself instead of an infection. It can damage to your tissues, shut down your organs, and even lead to death. Other symptoms of sepsis include:

• symptoms of infection
• changes in mental state
• feeling very sick, such as having a hard time breathing or feeling pain

Seek immediate medical help if you think you might have sepsis.

Hypothyroidism

Hypothyroidism occurs when your thyroid is not functioning properly. It does not create enough of your thyroid hormone for your body. Therefore, you may experience:

• a decreased body temperature
• fatigue
• dry skin
• mood changes
• constipation

You can take medication to improve your thyroid’s hormone production.

Advanced age

You may have a lower body temperature as you age. You may have less body fat in your arms and legs, dry skin, and a slowed metabolism as you get older. These can all contribute to a lower body temperature.

Medications

Taking certain medications could lower your temperature. These include beta-blockers and some antipsychotics.

Exposure to cold temperatures

Your temperature may be low if you have been outside in cold weather. Wear warm enough clothes and keep your head covered in cold weather. Avoid getting wet in cold weather.

Keeping babies in a normal temperature range is very important to avoid hypothermia or other illnesses. Some factors that could influence a baby’s temperature include:

• low birth weight
• prematurity
• their birth environment being too cold
• hypoglycemia
• infection

Take your baby’s temperature using the same method every time. Make sure the room is a comfortable temperature, and let the infant warm up if they have been brought in from the cold.

The best temperature-taking methods for infants and toddlers are:

• In the armpit. Place the thermometer in the middle of the armpit, and close the arm against the body. Wait 3 minutes for an accurate measurement, or follow the thermometer’s instructions.
• In the rectum. Put a protective sleeve over the thermometer and add a lubricant to it. Insert the tip of the thermometer in the rectum (no more than 2 centimeters) and wait 5 seconds before pulling it out and reading it, or follow the thermometer’s instructions.
• In the eardrum (for infants more than 3 months old). Place the thermometer into the ear, seal off the ear, and turn on the thermometer. Pull it out when the thermometer indicates it’s taken the reading.
• Contactless forehead: Some thermometers allow you to take a child’s temperature without contact. The thermometer and forehead must be movement-free to get an accurate reading. Press the temperature button. Your device will beep or flash to let you know the temperature is ready to be read.

Learn more about contactless thermometers here.

Call a healthcare professional if your temperature is 96°F (35.55°C) and you feel sick. You can describe your symptoms over the phone. They may offer a diagnosis or ask you to make an office visit.

You need immediate medical treatment if your temperature drops due to hypothermia or sepsis. Seek care if your temperature is declining and you have:

• breathing difficulty
• slowed speech
• confusion or other mental changes
• tiredness
• blue skin or lips

Infants with a low body temperature should be seen by a doctor immediately. Other symptoms of hypothermia in infants include red or discolored and cold skin, sleepiness, and disinterest in feeding.

Below are commonly asked questions regarding a low body temperature.

What causes a low temperature of 96F?

There are many different causes of low body temperature, including:

• incorrect temperature taking
• advanced age
• cold exposure or hypothermia
• certain health conditions

What does it mean when you have a low temperature?

Having a low body temperature can mean different things depending on its cause. It may mean that you have taken a temperature reading wrong or your living environment is too cold. A low temperature can also indicate an underlying health condition.

What illness causes low temperature?

Certain health conditions may cause a drop in body temperature, including hypothermia, hyperthyroidism, and sepsis.

What should I do if my body temperature is low?

If your body temperature is low, you should move to a warm, sheltered location as soon as possible and retake a temperature reading. If a low body temperature accompanies other symptoms such as breathing difficulty or skin changes, you should seek medical assistance.

There are several reasons you feel ill and have a thermometer reading of 96°F (35.55°C). You may have a serious illness like hypothermia or sepsis that requires immediate attention. You may have taken your temperature incorrectly. Or you may have another underlying factor contributing to the lower temperature like advanced age, medication use, or hypothyroidism.

Scientists no longer consider body temperature up to 37 degrees the norm: September 24, 2018, 07:05

Illustrative photo. © Pixabay

September 24, 2018, 07:05

14

You wake up at 6 am feeling sick and shivering. Not sure if you’re really sick or if it’s just a reaction to waking up, you resort to using a thermometer. It shows a temperature of 36.9degrees, so you roll out of bed with a groan and get ready for work. After all, this is not yet the condition that is called a fever. Is not it?

You are right. However, forget everything you know about “normal” body temperature and fever starting at 37 degrees. This is an outdated figure based on the results of a flawed study in 1868 (yes, conducted as much as 150 years ago!). The facts about proper body temperature show that things are much more complicated.

Firstly, there is no single indicator that could be recognized as the norm for all people. Normal body temperature in women is slightly higher than in men. And it is higher in children than in adults. The lowest value of body temperature is in the morning.

Body temperature of 37.2 degrees at six o’clock in the morning is far from normal, although the same temperature at four o’clock in the afternoon can be considered normal. A study published in the Journal of General Internal Medicine refutes below 37 degrees Celsius as the norm. It has been considered the normal temperature of the human body for centuries. According to the results obtained during the survey 329individuals found that the average body temperature in healthy adults is 36.5 degrees. As for the fever, the researchers found that it starts on average at 37.5 degrees.

But this does not mean that you should start to consider a lower value as the norm. Scientists are pushing for body temperature to be considered a flexible concept, considered in terms of age, gender, time of day and other factors – in many ways this concept is similar to how body weight is estimated based on height and how thresholds for normal blood pressure vary depending on by age and gender.

It is still difficult to invalidate an indicator up to 37 degrees. It continues to be referred to as the norm in major modern medical textbooks. As for the feverish state, doctors usually consider 38 degrees Celsius to be its lower limit. However, referring to the not entirely clear nature of the febrile state, experts note that the sensation of heat to the touch is also sufficient.

So if you feel like you’re developing a cold, then you probably are. Our internal thermostat is located in the hypothalamus, an almond-sized region of the brain that makes us sweat when we need to cool down and makes us shiver when we need to warm up. Body temperature rises in hot weather, when we exercise, and also after taking certain types of medications. In women, body temperature is also higher during ovulation and pregnancy.

The human body’s response to bacteria is characterized by the fact that molecules called pyrogens travel through the bloodstream to the hypothalamus, which reacts by raising body temperature. Fever helps your body fight infection by stimulating the body’s defenses, sending a sort of warning to the immune system. It also creates a more hostile environment for bacteria and viruses, making it harder for them to multiply. Although parents often panic when their children develop a fever, fever is more of a protection factor than an enemy.

If the patient’s temperature does not exceed 39 degrees, doctors usually advise not to bring it down. Your body is trying to maintain an elevated temperature no matter what you do. The most reasonable thing is to find the source of the infection and fight it. A temperature above 39 degrees is already a formidable sign that may require medical intervention in order to prevent a further increase in body temperature.

The study in question is not the first to challenge the idea of ​​a single standard measure of normal body temperature. So far, our society considers the usual 37 degrees to be the norm. This figure was the result of the work of Karl Reinhold August Wunderlich, a 19th-century German physician who wrote a seminal work using data from 25,000 patients. He came to the conclusion that temperatures up to 37 degrees are the normal “physiological point” of the body and that a feverish state develops starting from 38 degrees.

The “moment of truth” came when researchers gained access to one of the Wunderlich thermometers, which is located in the Mutter Museum of Medical History in Philadelphia, US. Tests have shown that this thermometer, which is a mercury-filled glass tube about 22 centimeters long, shows a temperature 2-3 degrees higher than modern digital thermometers. It was even calibrated higher than other thermometers from the same period in the museum’s collection.

Material prepared by Almaz Sharman, professor of medicine.
Read other useful articles on health and disease prevention at www.zdrav.kz.

The body has cooled down: what does low body temperature mean? Therapist and hematologist answers

Health

You decided to measure your body temperature, but it turned out to be below the usual 36. 6. Googled what low body temperature means (bad idea!) and found out that you have “suspected AIDS, cancer” or worse. Sobaka.ru asked Galina Kuznetsova, a hematologist at the CMD Center for Molecular Diagnostics of the Central Research Institute of Epidemiology of Rospotrebnadzor in St. Petersburg, should you panic if you have a low body temperature. Spoiler – no!

People got cold

In 1851, the German physician Karl Wunderlich measured the body temperature of 25,000 patients in Leipzig and found that the average temperature was 37 degrees Celsius. However, today it is believed that the body temperature of a healthy person is usually 36.6 degrees. To understand what this is connected with, scientists from Stanford University decided. In 2020, they analyzed data from three independent studies. The first took place from 1862 to 1930 and included 83900 veterans of the American Civil War, the second – data from the National Health and Nutrition Survey (5998 people, 1971-1975), the third – another independent study at Stanford, which included 230261 men from 2007 to 2017.

The authors noticed that the average temperature in the first sample was higher than in the second, and in the second – higher than in the third. It turned out that the temperature was dropping by about 0.004 degrees every year. As the reasons for this “cooling” the researchers named several reasons, for example, controlled ambient temperature. They believe that people began to cool the premises more often in order not to overheat, and this may affect their metabolic rate. The second reason was the state of health. A century and a half ago, infectious diseases were much more common, and inflammation developed more often in the human body, which required energy expenditure and increased body temperature. Now we manage to cope with it with the help of hygiene and anti-inflammatory drugs, and this “extra” temperature has disappeared.

What temperature is considered normal

Normal body temperature is considered to be 36.6 degrees, although it can fluctuate between 36. 2-36.9. A low temperature is considered to be below 36 degrees. This condition is also called hypothermia. It is usually accompanied by a decrease in heart rate, blood pressure and heart rate (heart rate).

“Low body temperature during repeated measurements should not be given too much importance. Its constancy depends on heat generation and heat loss / release. It may change during the day. The minimum is at night and in the morning, the maximum is during the period of activity. After a run, the temperature may briefly rise by a couple of degrees, and this is also normal. ”, The doctor says.

Why is the temperature dropping?

Instructions for using the most basic items are still needed – it turns out that many measure the temperature incorrectly! “The underestimation of the temperature may be due to the thermometer and the choice of the place of measurement. Mercury thermometers (quite a reliable tool!) Have sunk into oblivion due to the danger of mercury vapor poisoning when broken. Alcohol, on the contrary, are not very convenient, they can break when shaken, and not everyone can shake it correctly to reset the previous indicators. Thus, the measurement of body temperature at home is usually carried out with electronic thermometers, which have an error. The temperature of exposed areas of the skin can also be underestimated. It depends on the air temperature – remember how cold cheeks are in the cold, ”says Dr. Kuznetsova.

Decrease in temperature may be dependent on skin moisture – evaporation of moisture from the surface naturally cools locally. The measurement area is important – the temperature when measured in the mouth under the tongue will be half a degree lower than in the rectum, in the armpit half a degree lower than in the mouth. The temperature of the fingertips can be markedly reduced depending on the conditions and is of no clinical significance.

Another reason is age. In older people, metabolic processes and body temperature decrease.

How to cure SARS in 2 days and what to do if a colleague gets sick: stupid but important questions about a cold

1. Hypothyroidism – weak functioning of the thyroid gland
2. Asthenic syndrome – a condition in which a person has excessive fatigue, pronounced weakness, mood swings, a predominance of negative mood
3. The period of convalescence (the period of recovery of a person, characterized by the gradual disappearance of signs of the disease and the restoration of normal functioning of the body) after inflammatory diseases or chemotherapy
4. Low muscle mass
5. Fasting
6. Chronic intoxications
7. Uncontrolled use of painkillers

“If something is bothering you, there are suspicions that your condition is not just the influence of environmental factors and proposed circumstances, then, of course, seek the advice of a specialist. For starters, a therapist is fine. At the initial appointment, it will be possible to establish a range of possible problems that require additional research.