Hypothermia and cold.

Hypothermia is defined and classified, and the physiology of temperature regulation summarized; fluid balance and the phenomenon of symptomless cooling are considered in more detail. The symptoms and signs of hypothermia are charted, with cautions, and the problems considered of making any diagnosis, including that of death, in hypothermic patients. Recommendations for treatment are complicated by the possible presence of other factors including drowning and the so-called 'diving reflex' phenomenon. There are many methods of rewarming and all are safe if used with intensive care monitoring. However, for field use by the rescue services there are only three practical methods. The traditional explanation of why survivors die after rescue is discarded with an alternative proposed. Since hypothermia is not numerically the most important cause of cold-related deaths, the other dangers are considered. Finally caution is advised when interpreting published papers on hypothermia.