May 11 , 2020
Kids’ fevers are most often caused by viral illnesses like colds, but they can also result from bacterial infections like sinusitis and, more rarely, from serious health issues like autoimmune diseases and even leukemia. But before you start Googling those illnesses, you may want to consider whether your child definitely has a fever.
Foreheads can feel warm for any number of reasons—overbundling, vigorous play, even your own hand being cold. For the most accurate results, use a rectal thermometer to check your baby’s temperature or an oral thermometer for older children. Body temperature varies by more than 2ºF in a day, so doctors use strict cutoffs for fever, no matter what temperature a parent thinks her child “usually” runs.
We count a fever as a rectal temperature of 100.4ºF, an oral/ear/ forehead temperature of 100ºF, or an armpit temperature of 99ºF. Fevers can go much higher (106ºF) without harming your child. In fact, the height of a fever doesn’t correspond to the severity of a child’s illness. Call your pediatrician if your baby is younger than 3 months and has a fever or if your child’s fever persists for more than three days.