Temperature fluctuations in the lower limbs of young and elderly individuals during activities of daily living.

Age-related deficiencies in thermoregulation diminish the capacity to defend against heat loss under conditions often encountered during activities of daily living (ADL). A potential consequence of these deficiencies is that elderly individuals could have colder lower limbs, which would exacerbate the age-related decline in plantarflexor contractile properties and compromise recovery from a tripping incident. Moreover, a common self-perception among the elderly is that their limbs are cold. However, this impression has never been documented, especially under ADL conditions. Our objective was to test the hypothesis that elderly individuals have lower plantarflexor temperatures than their younger counterparts. Skin temperatures above the plantarflexors of elderly and young individuals were continuously recorded during ADL in the winter months and compared under three conditions: quiescent indoor temperature, during a cold challenge, and the recovery period subsequent to the cold challenge. For quiescent indoor periods, differences in skin temperature between the two groups were not statistically significant. During cold exposures, both age and exposure duration were statistically significant factors related to the decrease in skin temperature, with the elderly group maintaining warmer temperatures. In the recovery period following short duration cold exposures, a statistically significant difference between the two groups for the decrease in skin temperature persisted for the first 9min of recovery. The results do not support the hypothesis that the lower limbs of elderly participants are colder. Higher limb temperatures observed in elderly participants were consistent with previous studies of age-related thermoregulatory changes, indicating that deficiencies in vasoconstriction are persistent in ADL.