Temperature

Abstract

Most animals have survivable body temperature ranges falling somewhere between about −1°C and roughly +45°C. Below −1°C fairly drastic mechanisms are required to combat the possibility of freezing, while enzyme systems tend to become disrupted above 45°C. As is so often the case in biology there are a few exceptions to this general rule; volcanic pools with temperatures above 50°C often contain a thriving fauna, while some supercooled or glycerol-protected dormant insects may survive to −25°C, though of course these latter are immobile. On the other hand it should be remembered that most animals’ temperature ranges are far narrower than the overall limits given above. Even that adaptable tropical mammal, man, cannot survive indefinitely below about 15°C or above some 45°C without clothes, fire, shelter or considerable quantities of water.