Pay attention to signs and symptoms of a serious illness. Call your child’s doctor right away if your child has a fever and:
- Is younger than 3 months with a fever of 100.4°F or higher.
- Looks very sick, is unusually sleepy, or very fussy.
- Has a seizure.
- Has been in a very hot place such as a hot car.
- Has other symptoms such as a stiff neck, bad headache, severe sore throat, bad earache, a rash, or repeated vomiting or diarrhea.
- Has immune system problems, such as cancer or sickle cell disease.
- The fever goes higher than 104°F repeatedly.
- Your child acts sick even after the fever comes down.
- The fever lasts more than 2 days in a child younger than 2 years old.
- The fever lasts more than 3 days in a child older than 2 years older.