Ask the Experts; February 2006; Scientific American Magazine; by Peter Nalin, John Margrave; 1 Page(s)

Fever--an elevated body temperature--is usually related to stimulation of the body's immune system. (Normal temperature fluctuates from about one degree below 98.6 degrees Fahrenheit to one degree above that number.)

Fever can support the immune system's attempt to gain advantage over infectious agents, and it makes the body less favorable as a host for replicating viruses and bacteria, which are temperature sensitive.