Fever Facts

A fever is a sign that the body's natural defense against infection is working. Before calling a doctor, take note of other symptoms, such as headache, lethargy, loss of appetite and chills, which may be more important than fever.

Infants (3 months or younger) with a fever of 100.4s F (38sC) need medical attention. For older children, consider calling a doctor if temperature goes above 102s F (39s C) or persists for more than two or three days.

Body temperature varies according to time of day, gender, hormones, age and other factors. 98.6s (37s C) is only an approximation of "normal." Adults' normal temperatures may be anything from 96.4s to 99.4s F (35.7s C to 37.4 sC). Temperature tends to be lower in the morning and higher in the evening. Temperatures above 106s F (41s C) are life-threatening and need immediate treatment.