A temperature of 100.4°F (38°C) or higher is especially important in a baby younger than 3 months and needs prompt medical evaluation. For older children, the number matters less than breathing, alertness, hydration, associated symptoms, and whether the child is getting worse.
What counts as a fever?
A temperature of 100.4°F (38°C) or higher is generally considered a fever. The method used to measure temperature and the child's age both matter, so tell the pediatrician how and where the temperature was taken.
Fever is a sign, not a diagnosis. Viral infections are common causes, but the accompanying symptoms and the way a child looks and behaves often provide more useful clues than the temperature alone.
When should you contact a pediatrician promptly?
- The child is younger than 3 months and has a temperature of 100.4°F (38°C) or higher.
- The temperature repeatedly rises above 104°F (40°C).
- The child still looks or acts ill after the fever comes down, or seems to be getting worse.
- The fever lasts more than 24 hours in a child younger than 2 years, or more than 3 days in a child age 2 or older.
- The child has a weakened immune system, a serious chronic condition, or another symptom that concerns you.
Can telemedicine help with a fever?
An online visit can help a pediatrician assess breathing, alertness, hydration, rash, pain, vomiting, diarrhea, and other symptoms. It can also help decide whether home monitoring is reasonable or whether the child needs an examination, vital signs, urine testing, throat testing, or another in-person evaluation.
Telemedicine does not replace emergency care and cannot provide every hands-on examination or test. The safest next step depends on the child's age, medical history, symptoms, and appearance during the visit.
What can parents do while monitoring at home?
- Offer fluids regularly and watch urine output.
- Focus on comfort, breathing, alertness, and whether the child can drink and interact.
- Use fever medicine only according to weight-based directions from your pediatrician or the product label, and never give aspirin to a child unless specifically directed by a clinician.
- Write down the temperature, measurement method, timing, and associated symptoms for the visit.
Seek emergency care now for serious warning signs
Call 911 or go to the nearest emergency department when a child has fever with a life-threatening or rapidly worsening symptom.
- Severe trouble breathing, blue or gray color, or inability to speak or cry normally because of breathing difficulty
- Inability to wake, confusion, unusual unresponsiveness, or extreme weakness
- A seizure, stiff neck, or a purple or blood-colored rash
- Severe dehydration, such as very little urine, no tears, a very dry mouth, or being too weak or dizzy to stand
Sources reviewed
This general educational page was prepared using the sources below. It does not replace an individualized medical assessment.