Do Fevers Cause Brain Damage?

In This Article
Table of Contents

It has long been believed that high fevers can cause brain damage, especially if left untreated. While this can occur when the body temperature exceeds 107.6, a fever that high is extremely rare unless accompanied by hyperthermia.

Fevers are most commonly caused by viral or bacterial infections, but can also be due to toxins, cancer, or autoimmune diseases. A fever is just a symptom of illness, not an illness itself. When an otherwise healthy person has a fever because of an illness, it is unlikely to cause brain damage. Even febrile seizures, which occur in children, do not cause any permanent damage.

The time to be concerned about a high fever is when it is not caused by an illness, but because of overheating. This is actually heat stroke (hyperthermia), which is completely different than a fever. Hyperthermia can be caused by overexposure to high temperatures and under-consumption of water. In these cases, the body may not be able to regulate its temperature, and medications will not bring the temperature down. Brain and organ damage usually occur because of hyperthermia.

When to Be Concerned

Even if you or your child have not been exposed to high temperatures, and hyperthermia is not a concern, there are several other factors that play into deciding what to do about a fever.

In young children, take action based on your child's age and temperature:

  • Under 3 months: Call a doctor for any rectal temperature over 100.3 degrees
  • 3 to 6 months: Call a doctor for any rectal temp over 101
  • 6 to 12 months: Call a doctor for any rectal temp over 103

In children over 12 months and adults, there are other things to consider. Some situations that warrant calling a doctor include:

  • A child under age 2 who has a fever for over 24 to 48 hours
  • A fever that lasts longer than 48 to 72 hours in older children and adults
  • A fever over 105 degrees, which could indicate a more serious illness
  • Presence of other concerning symptoms such as a stiff neck, confusion, difficulty breathing, or a first-time seizure
  • Presence of other symptoms that make you think an illness may need to be treated, such as a sore throat, earache or a cough
  • You think you may have incorrectly dosed medication, or you aren’t sure what dose to give 


Generally, treatment is going to be based on how the person is feeling and acting. Fevers are actually helpful when the body has an infection because they make it more difficult for germs to live and multiply. The fever is actually your body’s natural way of fighting off the illness. The purpose of treating a fever is just to make the person more comfortable, not to eliminate the fever completely.

If an adult or child has a fever but feels okay, and is still able to perform daily activities or play, there is no reason to treat the fever. However, if the person is not feeling well enough to get out of bed or play, then it is fine to treat the fever with medication.

The most common and effective medications to treat fevers are :

  • Tylenol (acetaminophen): Tylenol is approved for use in children as young as 2 months old, but should never be given to a child under 3 months without first speaking to a doctor.
  • Advil or Motrin (ibuprofen): Ibuprofen is approved for use in children as young as 6 months.
  • Aspirin: Aspirin should never be given to children under 18 years of age, unless specifically recommended by a doctor, because of the risk of a rare but possibly fatal illness called Reye’s Syndrome.

A lukewarm bath may be helpful, but should only be tried after some medication has been given to prevent the temperature from rapidly rising after getting out of the water. If a bath makes your child uncomfortable or unhappy, it is unnecessary.

If a child has a fever and does not feel better about an hour after taking acetaminophen or ibuprofen (regardless of whether or not the temperature goes down), call his health care provider.

There are also other things you can do to help a person cope with a fever. Some tips:

  • Keep the person dressed lightly
  • Encourage her to stay well hydrated—drinking plenty of fluids can naturally cool the body and help prevent dehydration
  • Do not bundle someone who has the chills or use cold baths or alcohol rubs. These can all raise the core temperature of the body, making the person feel worse, not better. Using alcohol all over the body to bring down a fever can cause alcohol poisoning. 


If the high temperature is caused by overheating, heat exhaustion, or heat stroke, treatment is very different.

  • Remove the person from the warm area.
  • Sponge the person with cool water.
  • Place ice packs in the armpits, behind the neck, and in the groin area.
  • Give cool fluids if the person is alert (never try to hydrate a person who is unconscious). If you are concerned that someone is overheated and they are unconscious, call 911 immediately.
  • Seek medical attention, even if the person is awake.
  • Do not give medications, they may not help and could even be harmful.

The Bottom Line

Fevers can be scary, especially for parents who just want their children to feel better. However, not every case of fever warrants worry. The only time the body will sustain damage due to a high temperature is when the body temperature goes over 107.6 degrees. Unless the fever is caused by an outside source (hyperthermia) or there is already a neurological problem, there is almost no chance that this will happen.

Was this page helpful?

Article Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial policy to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Institutes of Health. Hyperthermia: Too Hot For Your Health.

  2. National Institutes of Health: MedlinePlus. Fever.