Your newborn may get upset for a variety of reasons – he may be hungry, tired or not feeling well. If he isn’t feeling well, a fever may be the sign of illness. But how do you know if your baby has a fever?
If your baby feels warm, looks flushed or is more fussy or less active than usual, he may or may not have a fever. The best way to determine this is by using a digital thermometer. We recommend against mercury thermometers, and instead recommend using a digital version.
Before you take a temperature, be sure to wash the thermometer in warm soapy water or rub with alcohol to sanitize it. Then rinse it with cool water. Temperatures may be measured rectally, orally (in the mouth), axillary (under the arm) or tympanic (in the ear). For infants, especially newborns, the recommendation is for temperatures to be taken rectally to assure the best accuracy.
If your newborn has a fever greater than 100.4 degrees, or a mild fever persists for more than 24 hours, you should call your pediatrician. Fevers tend to be a sign that the immune system is trying to fight off an illness, perhaps an earache, sore throat or more serious infection. Considering your baby can’t verbally tell you how he is feeling, a fever is one way he may show you that some illness is developing.
For more information on fevers and other common newborn illnesses, please talk with your UPMC Children's Community Pediatrics pediatrician.