Children's Health and Wellness

Fever in a Newborn

The system that controls body temperature is not well developed in a newborn. Call your baby's healthcare provider immediately if your baby is younger than 3 months old and has a rectal temperature of 100.4°F (38°C) or higher. 

Infection

A fever is common when an adult has an infection. In newborns, fever may or may not occur with an infection. A newborn may actually have a low body temperature with an infection. He or she may also have changes in activity, feeding, or skin color.

Overheating

It’s important to keep a baby from becoming chilled. But a baby can also become overheated with many layers of clothing and blankets. An overheated baby may have a hot, red, or flushed face, and may be restless. To avoid overheating:

  • Keep your baby away from any source of heat. For example, a room heater, fireplace, heating vent, or direct sunlight.

  • Keep your home at about 72°F to 75°F.

  • Dress your baby comfortably. He or she doesn't need more clothing than you do.

  • Cars can get very hot. Be extra careful when dressing your baby to go for a car ride.

Low fluid intake or dehydration

Newborns may not take in enough breastmilk or formula. This may cause an increase in body temperature. If you think your baby isn't eating enough of either breastmilk or formula, call his or her healthcare provider. Make sure you know how to check your baby's temperature and have a thermometer. Call your baby's healthcare provider right away if your baby has a fever.

Print Source: Up To Date. Evaluation and Management of Fever in the Neonate and Young Infant
Online Source: American Academy of Pediatrics. Fever and Your Babyhttp://www.healthychildren.org/English/health-issues/conditions/fever/Pages/Fever-and-Your-Baby.aspx
Online Source: American Academy of Pediatrics. Fever Without Fearhttp://www.healthychildren.org/English/health-issues/conditions/fever/pages/Fever-Without-Fear.aspx
Online Source: When to Call the Pediatrician: Fever, American Academy of Pediatricshttps://www.healthychildren.org/English/health-issues/conditions/fever/Pages/When-to-Call-the-Pediatrician.aspx
Online Source: Signs of Dehydration in Infants & Children, American Academy of Pediatricshttps://www.healthychildren.org/English/health-issues/injuries-emergencies/Pages/dehydration.aspx
Online Editor: Tchang, Kimberly
Online Medical Reviewer: Freeborn, Donna, PhD, CNM, FNP
Online Medical Reviewer: Lee, Kimberly G., MD, MSc, IBCLC
Date Last Reviewed: 11/1/2016
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