Time memory for heat exposure limited to a fixed daily time in heat-acclimated rats and humans

摘要

After daily heat exposure for 4-5 h limited to a fixed time for more than 5 consecutive days, body core temperature of rats and humans drops before and during the period them were previously exposed to heat. The fall in body temperature persists for a few days after terminating the timed daily heat exposure. Additionally. various thermoregulatory changes to resist heat are brought about especially during the specific period. It is, therefore. hypothesized that the thermoregulatory system can memorize the time for heat exposure and according to the memory, thermoregulatory responses for neutralizing heat stress are induced around the period corresponding to that of the previous heat exposure time even without actual heat exposure.