The therapeutic potential of regulated hypothermia

Reducing body temperature of rodents has been found to improve their surviv al to ischaemia, hypoxia, chemical toxicants, and many other types of insul ts. Larger species, including humans, may also benefit from a lower body te mperature when recovering from CNS ischaemia and other traumatic insults. R odents subjected to these insults undergo a regulated hypothermic response (that is, decrease in set point temperature) characterised by preference fo r cooler ambient temperatures, peripheral vasodilatation, and reduced metab olic rate. However, forced hypothermia (that is, body temperature forced be low set point) is the only method used in the study and treatment of human pathological insults. The therapeutic efficacy of the hypothermic treatment is likely to be influenced by the nature of the reduction in body temperat ure (that is, forced versus regulated). Homeostatic mechanisms counter forc ed reductions in body temperature resulting in physiological stress and dec reased efficacy of the hypothermic treatment. On the other hand, regulated hypothermia would seem to be the best means of achieving a therapeutic bene fit because thermal homeostatic systems mediate a controlled reduction in c ore temperature.