Fever: A Hot Topic
Fever is the regulation of body temperature at an elevated "set point." Contact with a variety of pathogens, such as viruses or bacteria, will result in the release of a small protein, endogenous pyrogen or interleukin 1, from the host's white blood cells. This protein circulates to the brain where it is thought to raise the temperature set point via the production of a prostaglandin. Fevers occur throughout the vertebrates. The cold-blooded vertebrates (fishes, amphibians, reptiles) raise their body temperature by behaviorally selecting a warmer microhabitat. Warm-blooded vertebrates (birds and mammals) use both physiological and behavioral means to raise core temperature. Over the past decade data from both in vitro and in vivo studies support the hypothesis that moderate fevers are beneficial to the host;that is, fever as evolved as an adaptation to reduce the severity of infection.