Rewarming of healthy volunteers after induced mild hypothermia: a healthy volunteer study.

OBJECTIVES The study compares the efficacy of two active and one passive warming interventions in healthy volunteers with induced mild hypothermia. METHODS Eight volunteers were studied in a random order crossover design. Each volunteer was studied during re-warming from a core temperature of 35 degrees C with each of: a radiant warmer (Fisher & Paykel); a forced air warmer (Augustine Medical), and a polyester filled blanket, to re-warm. RESULTS No significant differences in re-warming rates were observed between the three warming devices. It was found that the subject's endogenous heat production was the major contributor to the re-warming of these volunteers. Metabolic rates of over 350 W were seen during the study. CONCLUSIONS For patients with mild hypothermia and in whom shivering is not contraindicated our data would indicate that the rate of re-warming would be little different whether a blanket or one of the two active devices were used. In the field, this may provide the caregiver a useful choice.