Efficacy and safety of prehospital rewarming techniques to treat accidental hypothermia.

STUDY OBJECTIVE Evaluation of inhalation rewarming and peripheral rewarming for reducing the body core temperature afterdrop and accelerating rewarming rates. DESIGN Prospective, randomized human experimentation. SETTING Physiology laboratory with cooling during ice water immersion and rewarming in rescue sleeping bags in a windy, cold (2 C) air environment. TYPE OF PARTICIPANTS Eight experimental subjects who were cooled to clinical hypothermia (35.0 C), rectal or esophageal temperature (Tr or Te). MEASUREMENTS AND MAIN RESULTS Afterdrop was characterized as minimum Tr and Te plus recovery time to the Tr and Te levels at the onset of rewarming. Rewarming rates 30 and 60 minutes after maximum afterdrop for Tr and Te were measured. By analysis of variance, inhalation rewarming and peripheral rewarming evaluated separately or in combination did not significantly influence afterdrop duration, afterdrop recovery, or rewarming rates. CONCLUSION With no physiological benefit and hazards identified (inhalation rewarming burning the face, peripheral rewarming eliminating carbon monoxide equal to 300 to 600 ppm), inhalation rewarming and peripheral rewarming are not recommended for the prehospital treatment of mild hypothermia.