Core body temperature and sleep of older female insomniacs before and after passive body heating

The purpose of this study was to investigate the relationship between core body temperature and sleep in older female insomniacs and changes in that r elationship as a result of passive body heating (PBH). An increase in body temperature early in the evening by way of PBH in older female insomniacs i ncreased SWS in the early part of the sleep period and improved sleep conti nuity Fourteen older female insomniacs (60-73 years old) participated in at least two consecutive nights of PBH involving hot (40-40.5 degrees C) bath s 1.5 - 2 hours before bedtime. Hot baths resulted in a significant delay i n the phase of the core body temperature rhythm compared to baseline nights . This delay in temperature phase paralleled the improvements in sleep qual ity.