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Fever: Facts vs. Myths
Parent resource
Understanding fevers
Most importantly, have a reliable thermometer. If your thermometer gives different readings within a few minutes, it may not be accurate. For infants, the most reliable way to measure temperature is with a rectal thermometer.
When your child is sick, they need rest and fluids. If your child has a viral infection, it may take 3–5 days before they return to their usual activity level. Fever-reducing medicines can help your child feel better temporarily, but they do not help the body fight the infection or make the illness go away faster. These medicines usually work for 4–8 hours, and it is normal for the temperature to rise again as the medication wears off.
What a fever is
- A fever is a temperature of 100.4°F (38°C) or higher.
- Fever is a symptom, like a runny nose or a cough — it is not a disease.
- Fevers occur when the body responds to an infection and helps fight illness by activating the immune system.
Common myths
- All fevers are bad for children.
- Treating the fever will make the infection go away faster.
- Fevers cause brain damage.
- All fevers need to be treated with medicine.
- A fever is serious if it is high, or if you cannot bring the temperature down to normal.
The facts
- A fever is a temperature of 100.4°F (38°C) or higher.
- Temperatures below 100.4°F (38°C) are generally normal. Body temperature naturally fluctuates throughout the day.
- Avoid treating temperatures under 100.4°F unless directed by your healthcare provider.
- Viral infections commonly cause fevers that last 3–5 days.
- Fevers help children fight infections by activating the immune system.
- Children may feel warm for many reasons, including exercise, crying, warm weather, or being under blankets.
- If your child feels warm and seems ill, check their temperature. More important than the number on the thermometer is how your child looks and acts.
Treatment
- Low-grade fevers do not need to be treated if they are not causing discomfort.
- Fever-reducing medicines typically lower a temperature by about 1–2°F. It is not necessary for the temperature to return to normal.
- When the medicine wears off, it is normal for the fever to return.
- The two commonly used fever-reducing medicines are acetaminophen and ibuprofen. Ibuprofen is not recommended for infants younger than 6 months.
- We do not recommend routinely alternating acetaminophen and ibuprofen.
- Remember: low-grade fevers can help your child fight infection.
When to call your doctor
Contact us right away if your child has any of the following:
- Any infant younger than 3 months with a temperature of 100.4°F (38°C) or higher.
- Difficulty breathing.
- Signs of dehydration, such as very little urine, dry mouth, or no tears when crying.
- Severe headache, stiff neck, or unusual sleepiness.
- A fever lasting more than 5 days.
- Any time you are concerned about how your child looks or behaves.