1983 Henderson Award Lecture. Thermal homeostasis in old age.

The relationships of homeostasis to the physiologic and socioeconomic concomitants of aging are presented. Neurohumoral control of body temperature may become deranged in old age as a result of changes in the intrinsic regulatory system. Drugs and stressful climatic temperatures can have deleterious effects. Sensitivity of the elderly to environmental temperature changes is diminished, and their resources to control environmental temperatures are likely to be limited, leaving them more vulnerable than the young to hypothermia and hyperthermia.