Heat gain in the treatment of accidental hypothermia.

In two cases of accidental hypothermia, heated humidification of the inspired gases and warming of fluids administered intravenously was associated with an increase in the deep body (core) temperatures at rates of 0-5 degrees to 1-0 degrees C per hour. The first case demonstrated that heat was transferred selectively to the body core, as temperatures here rose during the first three hours of treatment, while skin temperatures remained low. The second patient gained less than 0-1 degrees C per hour when treated "passively" by means of surface insulation with unheated blankets. The introduction of "active" measures was followed by a more rapid gain. It is suggested that heat supplied to the body core by these measures provides effective additions to metabolic production, particularly when the deep body and cardiac temperatures are at their lowest.