Fevers, though they can be frightening, are rarely harmful and treatment is not always necessary. An above average body temperature can be caused by many things, including strenuous exercise, time of day (temperature rises in late afternoon), infection, environment (a hot room, a hot day, or being bundled up), a recent immunization or natural individual variations.

Fevers generally defined as a temperature of 38 degrees C (100 degrees F) or more whether taken orally, rectally, or auxiliary. A fever of 41 degrees C (105 degrees F) is considered high, although in general the height of the fever does not correlate to the seriousness of the illness. How sick a child acts and the cause and potential complications of the illness are the most important issues.

Fever is often the child’s body’s response to infection. Fever between 38 and 39 degrees C (100 and 102 degrees F) may help children fight off infections, and experts believe that fever should not be treated unless the child seems uncomfortable or the temperature is high enough to cause excessive fluid loss (over 39 degrees C (102 degrees F) for more than a few hours). The fever itself does no harm unless it is at or above 41 degrees C (106 degrees F) — a temperature that does not occur except when children are in very hot environments. The most significant sign of serious illness is a child who looks and acts very ill.

Important: Do not give aspirin to children under age 5. It can cause serious illness.