My Way Back to Contents Disorders of Temperature Regulation Overview Internal temperature is tightly controlled in humans and other warm-blooded animals by a series of feedback loops. At extremes of temperature, or in situations where the normal compensatory mechanisms can't work, serious injury can occur. Hypothermia An abnormally low core temperature. 82.4 - 89.6 Severe below 28 below 82.4 Mild hypothermia is most commonly encountered during general anaesthesia. Patients are unconscious and paralysed.
Body cavities are open permitting evaporation.
Theatres are often cooled to keep the surgical team comfortable. Controlled hypothermia is used in cardiac and neurosurgery to permit longer operating times. It is therefore difficult to distinguish between someone who is very cold and a corpse. Resuscitation continues until core temperature is normalised, at which time brain death can be confirmed or excluded. The big problem with moderate to severe hypothermia is that heart muscle becomes very irritable at low temperature.