When Should I Worry About a Fever? A Parent's Guide by Age

Fever is one of the most common reasons parents call the pediatrician. A rectal temperature of 100.4°F (38°C) or higher is considered a fever in infants.

Under 28 Days Old: Always Go In

A fever in a baby younger than 28 days is a medical emergency. Go to the emergency department right away regardless of how well your baby appears to be acting.

29 to 60 Days Old: Call Immediately

These infants still carry meaningful risk and are typically evaluated with blood work and urine testing.

61 Days to 3 Months: Call Your Pediatrician

A well appearing baby in this age group may sometimes be monitored at home, but this decision should always be made by your pediatrician.

3 to 6 Months: Watch and Respond

By this age most fevers are caused by common viral infections. Call if the fever lasts more than 24 hours or your baby seems unusually sleepy, irritable, or is refusing to eat.

6 to 12 Months: Focus on Behavior

The fever itself is less important than how your baby is acting. Call your pediatrician if the fever persists beyond 48 to 72 hours or new symptoms appear.

What Not to Do

Do not bundle a feverish baby in extra blankets, use ice baths or rubbing alcohol, alternate acetaminophen and ibuprofen without guidance, or give ibuprofen to a baby under 6 months.