Hypothermia OccursWhen Heat Output Exceeds Heat Production, so Body Temperature Decreases to Dangerous Levels

Small or sick animals exposed to a cold environment may lose more heat than they can generate, and body temperature may decrease to a point at which heat-regulating mechanisms no longer work. The ability of the hypothalamus to regulate body temperature is greatly impaired below a temperature of 29^oC (84^oF). Cardiac arrest occurs at around 20^oC (68^oF). Neo­nates seem to be able to withstand cooling more than adults, and apparently comatose lambs, piglets, and puppies can be revived through warming.