How do I know if my infant has a fever?

What temperature is considered a fever in a baby?

Fever: 100.4°F (38°C) or higher.

Normal Body Temp: 97°F and 100.3°F (36.1°C and 37.9°C)

When should you seek medical attention or advice if your newborn has a fever?

If your baby is under 12 weeks old with a fever, seek medical attention immediately. This is an emergency and you need to take your baby to the nearest emergency department.

Signs that can indicate a fever in a newborn:

• Acting fussy or irritable

• Poor feeding or refusing to eat

• Difficulty sleeping or sleeping more than usual

• A rectal temperature of 100.4°F (38°C) or higher
  
  Le Saux N. The febrile infant (29 to 90 days of age): Outpatient evaluation. UpToDate. Updated Apr 16, 2021. Available from: https://www.uptodate.com/contents/the-febrile-infant-29-to-90-days-of-age-outpatient-evaluation. Accessed on May 4, 2023.

  “Fever in a Newborn Baby.” Nationwide Children's Hospital, Nationwide Children's Hospital, www.nationwidechildrens.org/conditions/health-library/fever-in-a-newborn-baby. Accessed 14 Aug. 2024.