Do Fevers Cause Brain Damage?

A fever, especially a high and/or prolonged one, can be a concern for several reasons. But, one thing you likely do not need to worry about is resulting brain damage.

When an otherwise healthy person has a fever due to, say, a viral or bacterial infection, it is unlikely to cause brain damage. Even febrile seizures, which occur in children, do not cause any permanent damage. While there is such a risk if one's body temperature exceeds 107.6 degrees F, a fever that high is extremely rare. The time to be concerned about a high fever is when it is not caused by an illness, but because of overheating, i.e. heat stroke (hyperthermia).

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.

Young woman feeling symptoms of an illness
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When to Call a Doctor

Even if you or your child have not been exposed to high environmental 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 a rectal temperature of 100.4 degrees F or higher
  • a child of any age: Call a doctor when temp rises above 104 degrees F repeatedly

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 F, 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 

Fever Treatment

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. It's actually your body’s natural way of fighting off 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 OK, 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 do these things, you might consider treating the fever with medication.

The most common and effective medications to treat fevers are:

  • Tylenol (acetaminophen): Tylenol is approved for use in adults and 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 adults and 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 you or your child uncomfortable, 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 their healthcare provider.

There are also other things you can do to help ease symptoms with a fever:

  • Dress in light fabrics. Avoid bundling up and wearing layers.
  • Drink plenty of fluids, which can naturally cool the body and help prevent dehydration.
  • Do not use cold baths or alcohol rubs. These can all raise the core temperature of the body, increasing discomfort. Using alcohol all over the body to bring down a fever can cause alcohol poisoning. 

Hyperthermia Treatment

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

  • Remove yourself/the person from the warm area.
  • Sponge the skin 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 take/give medications: They may not help and could even be harmful.

A Word From Verywell

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.

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Article Sources
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  1. American Academy of Pediatrics. Febrile seizures. Updated November 30, 2017

  2. National Institutes of Health. Hyperthermia: Too Hot For Your Health.

  3. American Academy of Pediatrics. When to call the pediatrician: fever. Updated November 21, 2015

  4. National Institutes of Health: MedlinePlus. Fever.