Metabolic and thermal response of Eskimos during muscular exertion in the cold

¹ Institute of Work Physiology, Blindern, Oslo, Norway, National Research Council, Ottawa, Canada, John B. Pierce Foundation of Connecticut Inc., New Haven, Connecticut, Department of Medicine, Dalhousie University, Halifax, Nova Scotia

Performing muscular work in cold surroundings results in a greater energy requirement than that in a neutral environment at low levels of work, but is the same as that in a neutral environment at higher levels of work when rectal temperature is increased by the work. No higher heat production could be demonstrated in Eskimos than in Caucasians. It was found that rectal temperature increases during muscular work up to a certain level, this being almost constant over a wide range of environmental temperatures if the rate of work is constant. But when work rate becomes sufficiently low, the heat production is too small to compensate for the increased heat loss in the cold, so that the rectal temperature falls. A quicker onset of the rewarming of the previously cooled skin of the hands was found in Eskimos than in Caucasians as a result of exercise in the cold. This suggests a different vasomotor control of the blood supply to the skin.