What is a fever?

A fever is a higher-than-normal body temperature. It’s a sign of your body's natural fight against infection.

  • For adults, a fever is when your temperature is higher than 100.4°F.
  • For kids, a fever is when their temperature is higher than 100.4°F (measured rectally); 99.5°F (measured orally); or 99°F (measured under the arm).

The average normal body temperature is 98.6° Fahrenheit (or 37° Celsius). When you or your child’s temperature rises a few degrees above normal, it’s a sign that the body is healthy and fighting infection. In most cases, that’s a good thing.

But when a fever rises above 102°F it should be treated at home and, if necessary, by your healthcare provider if the fever doesn’t go down after a few days.

What do I do when my child has a fever?

With most cases, a slight fever isn’t a cause for concern with children. A low fever can make a child uncomfortable, it isn’t unusual for them to seem unaffected, still playful and eating and drinking normally, though maybe a bit more tired. Their fever should resolve in a few days.

With higher fevers, call your child’s healthcare provider if:

  • Your child’s fever lasts more than five days.
  • It’s higher than 104°F.
  • The fever is not reduced by medications such as ibuprofen or acetaminophen. (Do not give a child under 17 aspirin due to the risk of Reye's syndrome.)
  • You are concerned that the child isn’t behaving in their usual way, or anything else makes you uncomfortable with their fever or illness.

Some children have a frightening side effect to fever called febrile seizures. This happens in 2% to 4% of children under age 5. Some seizures cause jerking movements, or it may look like your child has passed out. When this happens put your child on their side, do not put anything in their mouth and call 911 if the seizure lasts more than five minutes and/or the child’s lips turn blue.

If it lasts less than five minutes, notify your healthcare provider and go out and get medical attention right away.

What are symptoms of a fever?

The main symptoms of a fever include:

  • Elevated temperature (above 100.4°).
  • Chills, shivering, shaking.
  • Body aches and headaches.
  • Fatigue (tiredness).
  • Intermittent or constant sweating.
  • Flushed complexion or hot skin.

Last reviewed by a Cleveland Clinic medical professional on 12/31/2019.

References

  • American Academy of Family Physicians. Fever. Accessed 1/6/2020.
  • Hague R. Managing the child with a fever. Practitioner. 2015;259(1784):17-21, 2-3.
  • NHS Choices. Fever in children. Accessed 1/6/2020.
  • Merck Manual. Fever. Accessed 1/6/2020.

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