Laboratory comparison of technique for rewarming hypothermic casualties

The efficacy of inhalation, hot bath, piped suit and spontaneous rewarming have been directly compared under controlled conditions. Hot bath rewarming was significantly more effective at raising deep body temperature than the piped suit technique and both were more effective than the other two methods. The effect of inhalation rewarming was not significantly different from that of spontaneous rewarming. All techniques gave rise to afterdrops of core temperature of widely varying degrees and durations. It is concluded that inhalation rewarming should not be employed if it entails a delay in transporting a patient to a facility for rapid external rewarming. Piped suit rewarming is a convenient field alternative to the use of a hot bath and a simple apparatus for carrying this out is described. The sluggish response of rectal temperature to cooling and rewarming in this study suggests that it should not be relied upon as the sole indicator of a patient's thermal state during treatment. Auditory canal temperature is a more valid substitute.