Why Do Fevers Happen?

Fevers often happen when a child has an infection or other illness. A fever helps the body stimulate the immune system to fight the infection or illness. Experts believe turning up the heat makes the body a less comfortable place for germs that cause illness.

In healthy kids, fevers aren’t usually a sign of a serious problem.

When Is a Fever a Sign of Something Serious?

A fever can be serious for:

• Infants younger than 3 months: If an infant younger than 3 months has a rectal temperature of 100.4°F (38°C) or higher, call your doctor or go to the emergency department right away.
• Kids with some health conditions: If your child has an ongoing health issue, make sure you know if the doctor should be called for fever.

If your child has a fever and other symptoms, like a stomachache or sore throat, call the doctor. A good sign that it’s nothing serious is if your child is 3 months or older and:

• is still interested in playing
• is drinking well
• is alert and smiling
• has a normal skin color
• looks well when their temperature comes down

What Else Should I Know?

Fevers usually don’t need treatment. Home care (rest, plenty of fluids) often is enough to manage a fever. Acetaminophen or ibuprofen can ease discomfort, but kids or teens should not take aspirin, which has been linked to a rare but serious illness called Reye syndrome.

Kids with a fever should stay home from school, work, or childcare until their temperature has been normal for 24 hours without the use of fever-reducing medicines.