During 7 hours of comfortably warm sleep, average metabolic rates of 11 Indian and 7 white men were alike. Since the Indians were 15% lighter their metabolic rates (MR's) referred to weight were greater. During a night at 0° with insufficient covering, MR's rose to 129% and 132% in the two groups. Cold caused equal myographic records of shivering (15% and 13% of records) and gross muscular movement appeared in 6.5% of the records for each group. Encephalograms showed that Indians slept more (51%) than whites (31%). Shivering was recorded in Indians and white men during encephalographic indications of sleep. Rectal temperatures of Indians declined about 0.5°. During cold nights skin on the bodies of all subjects cooled 3°–5° and about 15° on the feet. All subjects were disagreeably cold, but their cold sensations stimulated metabolic heat production only half as much as would be necessary to maintain fairly comfortable warmth.
Submitted on August 3, 1959