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Dangerous Body Temperature: Understanding and Managing High Fevers

by alexxlab

What qualifies as a fever in adults and children. How high is too high for body temperature. When should you seek medical attention for a fever. What are effective at-home remedies for managing fevers.

Содержание

Understanding Normal Body Temperature and Fever Thresholds

Body temperature is a crucial indicator of health, but what exactly constitutes a “normal” temperature? For adults, the average body temperature is often cited as 98.6°F (37°C), but this can vary. A more accurate range for normal body temperature is between 97°F (36.1°C) and 99°F (37.2°C). Temperatures within this range, even if they feel high to an individual, are generally not cause for concern.

So when does a temperature cross the threshold into fever territory? A true fever is typically defined as a body temperature of 100.4°F (38°C) or higher. This elevation in temperature is often the body’s natural response to infection or illness, as the immune system works to combat invading pathogens.

Why do fevers occur?

Fevers are essentially the immune system’s way of creating an inhospitable environment for harmful bacteria and viruses. By raising the body’s temperature, the immune system can more effectively fight off infections. While uncomfortable, a fever is often a sign that your body is actively working to heal itself.

  • Stimulates immune system response
  • Creates unfavorable conditions for pathogens
  • Accelerates production of white blood cells

Fever in Children: Special Considerations

When it comes to fevers in children, parents often find themselves particularly concerned. It’s important to note that children tend to spike fevers more quickly and at higher temperatures than adults. This is primarily due to their less experienced immune systems, which are still learning to respond to various pathogens.

For infants under 3 months old, any fever (temperature of 100.4°F or higher) is considered serious and requires immediate medical attention. For older children, fevers up to 102°F can often be managed at home, but it’s crucial to monitor for other symptoms and consult a pediatrician if there are concerns.

How do you accurately measure a child’s temperature?

Accurate temperature measurement is crucial for assessing fever in children. The most reliable methods include:

  1. Rectal thermometer (for infants)
  2. Oral thermometer (for older children)
  3. Tympanic (ear) thermometer
  4. Temporal artery thermometer

Always follow the manufacturer’s instructions and consult with your pediatrician about the most appropriate method for your child’s age.

At-Home Fever Management Techniques

For low-grade fevers in both adults and children, there are several effective at-home remedies that can help alleviate discomfort and support the body’s natural healing process.

Rest and Recovery

One of the most important things you can do when experiencing a fever is to get plenty of rest. Your body needs energy to fight off the underlying cause of the fever, so it’s crucial to give yourself time to recover. Sleep in light, breathable clothing to help regulate your body temperature and prevent overheating.

Hydration is Key

Fevers can lead to increased fluid loss through sweating, so staying hydrated is essential. Water is always a good choice, but you may also benefit from drinks that replenish electrolytes. For infants and young children, oral rehydration solutions can be particularly helpful in preventing dehydration.

Over-the-Counter Medications

For adults with temperatures below 102°F and minimal discomfort, over-the-counter medications can provide relief. Options include:

  • Ibuprofen
  • Naproxen
  • Acetaminophen
  • Aspirin (not recommended for children due to the risk of Reye’s syndrome)

For children, acetaminophen or ibuprofen can be used, but it’s crucial to follow dosing instructions carefully based on the child’s age and weight. Always consult with a pediatrician before administering any medication to children.

When to Seek Medical Attention for a Fever

While many fevers can be managed at home, there are certain situations where medical attention is necessary. Understanding these thresholds can help you make informed decisions about when to contact a healthcare provider.

High Fever Thresholds

For adults, a fever of 104°F (40°C) or higher warrants immediate medical attention. This high of a temperature can potentially lead to complications and may indicate a severe underlying condition.

For children, the threshold for seeking medical care is lower. If a child’s fever reaches 102°F (38.9°C) or higher, it’s advisable to consult with a pediatrician. Additionally, any fever in an infant under 3 months old should be evaluated by a healthcare professional immediately.

Accompanying Symptoms That Require Medical Attention

In addition to high temperatures, certain symptoms accompanying a fever should prompt you to seek medical care. These include:

  • Seizures
  • Loss of consciousness
  • Stiff neck
  • Difficulty breathing
  • Severe pain
  • Swelling or inflammation in the body
  • Pain during urination
  • Unusual vaginal discharge

For children, additional concerning symptoms include:

  • Non-blanching dark rashes
  • Extreme irritability or lethargy
  • Difficulty moving a part of the body, especially the neck
  • Rapid or labored breathing
  • Poor appetite or fluid intake resulting in decreased urine output

Fevers in Cancer Patients: Special Considerations

For individuals undergoing cancer treatment, fevers take on added significance. Cancer and its treatments can weaken the immune system, making patients more susceptible to infections. In these cases, even a low-grade fever may be cause for concern and should be reported to the oncology team promptly.

Why are cancer patients more vulnerable to infections?

Cancer treatments such as chemotherapy and radiation therapy can suppress the immune system, reducing the body’s ability to fight off pathogens. This immunosuppression can make even minor infections potentially serious for cancer patients.

What should cancer patients do if they develop a fever?

Cancer patients should follow the guidelines provided by their oncology team regarding fever management. Generally, any fever of 100.4°F (38°C) or higher should be reported immediately, as it could indicate a serious infection that requires prompt treatment.

The Role of the Hypothalamus in Body Temperature Regulation

Understanding how the body regulates temperature can provide insight into the fever process. The hypothalamus, a small region at the base of the brain, acts as the body’s thermostat. It works to maintain a steady internal temperature, typically around 98.6°F (37°C), though this can vary slightly throughout the day.

How does the hypothalamus respond to infection?

When the body encounters an infection, the immune system releases substances called pyrogens. These pyrogens signal the hypothalamus to raise the body’s set point temperature. This results in what we experience as a fever, as the body works to create an environment less hospitable to invading pathogens.

Fever Myths and Misconceptions

Despite the prevalence of fevers, there are many misconceptions about their causes, effects, and treatments. Addressing these myths can help individuals make more informed decisions about fever management.

Is it necessary to “sweat out” a fever?

Contrary to popular belief, bundling up to induce sweating is not an effective way to treat a fever. In fact, this can lead to overheating and dehydration. Instead, dress in light, breathable clothing and maintain a comfortable room temperature.

Do fevers always indicate a serious condition?

While fevers can be concerning, they don’t always signify a severe illness. Many common viral infections can cause low-grade fevers that resolve on their own with rest and proper care. However, it’s important to monitor fever symptoms and seek medical attention if they persist or worsen.

Is “feed a cold, starve a fever” sound advice?

This old adage has little scientific basis. When you have a fever, it’s important to stay hydrated and nourished. Eat light, easily digestible foods if you have an appetite, but don’t force yourself to eat if you’re not hungry. The most crucial aspect is maintaining proper hydration.

The Impact of Fever on the Body

While fevers are often beneficial in fighting infections, they can have various effects on the body, especially when they reach higher temperatures or persist for extended periods.

Metabolic Changes During Fever

During a fever, the body’s metabolic rate increases. For every degree Fahrenheit of temperature elevation, the metabolic rate can increase by about 7%. This increased metabolism can lead to:

  • Increased heart rate
  • Faster breathing
  • Higher calorie burn
  • Increased fluid loss

Cognitive Effects of Fever

High fevers can sometimes affect cognitive function, particularly in older adults or individuals with pre-existing neurological conditions. These effects may include:

  • Confusion or delirium
  • Difficulty concentrating
  • Irritability
  • In severe cases, hallucinations

It’s important to note that these cognitive effects are typically temporary and resolve as the fever subsides.

Fever Prevention Strategies

While not all fevers can be prevented, there are steps you can take to reduce your risk of developing infections that may lead to fevers.

Hygiene Practices

Maintaining good hygiene is crucial in preventing the spread of infectious diseases. Key practices include:

  • Regular handwashing with soap and water
  • Using hand sanitizer when soap and water aren’t available
  • Avoiding touching your face, especially your mouth, nose, and eyes
  • Covering your mouth and nose when coughing or sneezing

Vaccination

Staying up-to-date on recommended vaccinations can significantly reduce your risk of developing certain infectious diseases that may cause fevers. This is particularly important for:

  • Children, who should follow the recommended childhood vaccination schedule
  • Adults, who may need booster shots or additional vaccines based on age, health conditions, or travel plans
  • Elderly individuals, who may benefit from vaccines such as the high-dose flu shot

Healthy Lifestyle Choices

Maintaining overall health can help support your immune system and reduce your susceptibility to infections. Important lifestyle factors include:

  • Getting adequate sleep
  • Eating a balanced, nutritious diet
  • Engaging in regular physical activity
  • Managing stress through relaxation techniques or mindfulness practices

The Future of Fever Management

As medical science advances, new approaches to understanding and managing fevers are emerging. These developments may change how we approach fever treatment in the future.

Personalized Fever Management

Research is ongoing into how individual factors such as genetics, age, and overall health status affect fever responses. This could lead to more personalized approaches to fever management, tailoring treatments to each patient’s unique physiological profile.

Advanced Temperature Monitoring Technologies

New technologies are being developed for continuous, non-invasive temperature monitoring. These could provide more accurate and timely data on body temperature fluctuations, allowing for earlier intervention when necessary.

Novel Antipyretic Medications

Researchers are exploring new antipyretic (fever-reducing) medications that may offer more targeted or efficient fever management with fewer side effects. These could potentially provide better options for managing fevers, especially in high-risk populations.

Understanding fevers and knowing how to manage them effectively is crucial for maintaining health and well-being. While fevers can be concerning, they are often a sign that your body is working to fight off infection. By recognizing the signs of a dangerous fever and knowing when to seek medical attention, you can ensure that you or your loved ones receive appropriate care when needed. Remember, when in doubt, it’s always best to consult with a healthcare professional for personalized advice and treatment.

What to do and when to worry

Cold & Flu

by




Pallavi Mukkamala, MD


Jul
7,
2020

Having a fever can leave you feeling miserable, hot and sweaty — and worried. How high is too high? When is it time to call the doctor? What do these numbers even mean? 

We tend to fear fevers. However, a fever generally means your immune system is doing its job by fighting off infection. A fever is a stimulation of the immune system and is the immune system’s attempt to gain advantage over bacteria or a virus. 

What qualifies as a fever?

Normal body temperature for adults is about 98.6 degrees Fahrenheit but given that body temperature varies, the normal range is broad. It is very normal for body temperature to range between 98.6-99.9 and these temperatures (even if they are high for you) are less likely to be a true sign of illness.  

Regular body temperatures generally do not exceed 99.9 degrees Fahrenheit. Therefore, a true fever is when body temperature reaches 100.4 F (38 deg C). 

Parents, it’s easy to panic when your young child spikes a fever but first, take a deep breath. Keep in mind that kids usually spike fevers faster than adults and the temperatures tend to be higher as well; this is because children have an inexperienced immune system. 

At-home fever remedies

Fortunately, for low-grade fevers, there are a few steps you can take to make yourself more comfortable at home.

Rest

Your body needs lots of rest to give your immune system a chance to recover. Keep your body cool by sleeping with light clothing.

Fluids

Fluids are essential since fevers can cause fluid loss and dehydration. For children younger than 1 year old, use oral rehydration products.  

OTC medication

Fever treatment for adults usually depends on the temperature. If the temperature is below 102 degrees and there is minimal discomfort, simple over the counter ibuprofen, naproxen, acetaminophen or aspirin should be adequate.  

OTC medications should be used for children based on age and weight. Acetaminophen or ibuprofen can help reduce aches and pains, but parents should follow the directions and dose very carefully. Talk to your pediatrician about any medication questions.

When to call your doctor

If your fever reaches higher than 104 degrees Fahrenheit, come in to see your doctor. Also see your doctor if you have additional symptoms such as:

  • Seizures
  • Loss of consciousness
  • Stiff neck
  • Trouble breathing
  • Severe pain
  • Swelling or inflammation in the body
  • Pain with urination
  • Any malodorous vaginal discharge

If your child is less than 3 months old and has a fever, seek care immediately. For children older than 3 months old, seek medical care if their fever reaches 102 degrees Fahrenheit or higher. 

Fever with any of the following symptoms can also be a cause for concern in children:

  • Non-blanching dark rashes
  • Extreme irritability or lethargy
  • Severe pain
  • Difficulty moving a part of the body (most importantly the neck)
  • Trouble breathing or quick/forceful breathing
  • Poor appetite or fluid intake with decreased urine output

If ever in doubt, please reach out to your primary care physician. We can help you evaluate your symptoms and guide you in the right direction so you or your child can get the care you need.

Worried about a fever? Find a doctor near you or schedule a virtual visit today.

Fever | Coping physically | Cancer Research UK

Having a fever means your body temperature is higher than normal. Something inside your body has caused your temperature to rise.

There are a few possible causes of fever, the most common is an infection. Some cancer treatments can make you more at risk of infection. Other causes of a fever include the cancer itself or having a reaction to a drug. Sometimes the cause of the fever might be unknown. 

What is a fever?

When you have a fever, your body temperature rises above 37.5C (99.5F). This usually means there is something wrong somewhere.

A part of the brain called the hypothalamus controls your body temperature. Normally, the hypothalamus keeps the temperature of the inside of your body at around 37C (98. 6F). This can vary depending on the time of day and what you’re doing. But generally, it stays between 36.5 and 37C.

Fever is a common symptom in people with all types of cancers. It can be very uncomfortable and cause a lot of concern for you and those looking after you. If you have cancer and develop symptoms of a fever or infection it might not be serious. But in some situations, it could be a sign of a very serious infection.

The earlier an infection or fever is treated, the less likely you will have complications. It’s very important that your healthcare team find out what is causing the fever so they can treat it quickly and in the best possible way.
 

What to do if you have a raised temperature

If you’re having cancer treatment and your temperature goes above 37.5C call your advice line straight away. You should have a number to call them on 24 hours a day. 

What is an infection?

An infection is an invasion and growth of germs in the body. The germs could be:

  • bacteria
  • viruses
  • yeast
  • fungi or other microorganisms

Infections can start anywhere in the body and can spread throughout the body. Depending on where the infection is you may get a fever. You can also feel weak and drowsy and have shortness of breath.

How the body reacts to an infection

Fever is your body’s way of letting you know something is wrong. The fever helps to fight off your infection.

This happens in 3 phases.

Your body reacts and heats up

Your blood and lymphatic system make white blood cells. They are part of our immune system which fights infection. When you have an infection, you make lots of these cells. They work faster to try and fight off the infection.  

How we develop a fever is very complex. When our immune system recognises harmful bacteria or viruses the hypothalamus releases a hormone in response to this. The blood vessels in our skin start to narrow (constrict) so we lose less body heat. And the muscles contract, this makes you shiver. Both these cause the body to warm up and our temperature starts to rise. 

An increase in body temperature makes it harder for the bacteria and viruses that cause infections to survive. So, it helps your body fight the infection. 

The fever levels off

In the second phase of a fever, the amount of heat you make and lose is the same. So the shivering stops and your body remains at its new high temperature.

Cooling down

In the third phase, your body starts to try and cool down so that your temperature can return to normal. The blood vessels in the skin open again, so blood moves back to these areas. You sweat, which helps to cool the skin and cool down your body.

This phase of a fever may or may not happen naturally. You may need to have some medication to help relieve the symptoms, as well as treating the cause of the fever.

Who is most at risk of having complications?

The very young and elderly are more likely to get complications from a fever. In the elderly the hypothalamus does not work as well as it does in the young. The body temperature can rise too much, causing heart problems and confusion.

Children under 6 might have a fit (seizure) if their temperature gets too high. But in most people, the cause of the fever, such as infection, is more likely to cause problems than the fever itself.

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    UK Oncology Nursing Society (UKONS), March 2018.

  • Neutropenic sepsis: prevention and management of neutropenic in people with cancer
    National Institute for Health and Care Excellence, September 2012.

  • Regulation of body temperature by the nervous system
    C L Tan and Z A Knight
    Neuron, 2018. Volume 98, Issue 1, Pages 31 – 48.

  • Emerging challenges in the evaluation of fever in cancer patients at risk of febrile neutropenia in the era of COVID-19: a MASCC position paper

    T Cooksley and others

    Supportive Care in Cancer, 2021. Volume 29, Pages 1129–1138

  • Fever in Patients With Cancer
    Y Pasikhova
    Journal of the Moffitt Cancer Center, 2017. Volume 24, Issue 2, Pages 193 – 197.

  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. If you need additional references for this information please contact [email protected] with details of the particular risk or cause you are interested in.  

Last reviewed: 

19 May 2023

Next review due: 

19 May 2026