Fever in children is usually caused by infection. It also can be caused by chemicals, poisons, medicines, an environment that is too hot, or an extreme level of overactivity. Take the child’s temperature to see if he has a fever. Most pediatricians consider any thermometer reading above 100.4°F (38°C) as a fever. However, the way the child looks and acts is more important than how high the child’s temperature is.

Call the pediatrician right away if the child has a fever and:

  • Appears very ill, is unusually drowsy, or is very fussy
  • Has other symptoms such as a stiff neck, a severe headache, severe sore throat, severe ear pain, an unexplained rash, repeated vomiting or diarrhea, or difficulty breathing
  • Has a condition causing immune suppression (such as sickle cell disease, cancer, or chronic steroid use)
  • Has had a first seizure but is no longer seizing
  • Is younger than 2 months and has a temperature of 100.4°F (38°C) or higher
  • Has been in a very hot place, such as an overheated car

To make the child more comfortable, dress him in light clothing, give him cool liquids to drink, and keep him calm. The pediatrician may recommend fever medicines. Do NOT use aspirin to treat a child’s fever. Aspirin has been linked with Reye syndrome, a serious disease that affects the liver and brain.