Effects of aging on human cold tolerance

Abstract

The risk of hypothermia is widely considered to be greater for older than younger persons due to a reduced ability to maintain body temperature during cold exposure. Epidemiological surveys of body temperature normally maintained by older persons while in their own homes do not indicate a large incidence of hypothermia. Uncontrolled ambient conditions during body temperature measurements may have influenced those observations. Comparisons of the thermoregulatory responses to cold stress in younger and older subjects have been performed under controlled conditions in laboratory experiments. Results of these laboratory studies indicate that older men appear less able than younger men to defend their core temperature during experimental cold exposures. Cold exposure may elicit a slightly smaller rise in metabolic heat production, and the cutaneous vasoconstrictor response to cold may be slower in older than younger men. These aging effects may be limited, however, to men. In a recent study, older women appeared to defend core temperature during cold exposure as well as, or better than younger women. The possibility that preventable changes in body composition and physical fitness, rather than aging per-se, may account for impaired thermoregulatory responses to cold has not been adequately studied.