Thermoregulation is the ability of an
organism to keep its
body temperature within certain boundaries, even when the surrounding temperature is very different. A thermoconforming organism, by contrast, simply adopts the surrounding temperature as its own body temperature, thus avoiding the need for internal thermoregulation. The internal thermoregulation process is one aspect of
homeostasis: a state of dynamic stability in an organism's internal conditions, maintained far from equilibrium with its environment (the study of such processes in
zoology has been called
physiological or physiological ecology). If the body is unable to maintain a
normal temperature and it increases significantly above normal, a condition known as
hyperthermia occurs. For humans, this occurs when the body is exposed to constant temperatures of approximately , and with prolonged exposure (longer than a few hours) at this temperature and up to around death is almost inevitable. Humans may also experience lethal hyperthermia when the
wet bulb temperature is sustained above for six hours. The opposite condition, when body temperature decreases below normal levels, is known as
hypothermia.
