ABSTRACT
The ability to elevate body temperature in a controlled manner in response to injury or infection is highly conserved throughout both vertebrate and invertebrate species. Even the single-celled paramecium is capable of a regulated increase in its core temperature (a febrile response) (1). It seems unlikely that such an energy-expensive response would be so near universally present in the animal kingdom if it were not beneficial. Fever has been both deliberately induced and aggressively suppressed, and considered both a good and a bad prognostic sign. Accordingly, core temperature is one of the vital signs routinely monitored in trauma and critically ill patients.
