Effect of Cold on EEG Patterns and Body Temperature during Sleep

Sleep stages, as measured by electroencephalographic tracings, and rectal and skin temperatures of two young Caucasian males were recorded for eight nights in test environments at North Bay, Ontario, in Febryary, 1975. During the first three and last two nights, they slept in thermoneutral environments and during the intermediate nights they slept in an unheated tent at ambient temperatures ranging from -3 C to -12 C. Both subjects experienced a deprivation of rapid eye movement (REM) sleep; however, no rebound phenomenon was seen on return to thermoneutral conditions. In confirmation of earlier well-substantiated observations, it was observed that the subject who showed more delta sleep in the cold was the one with the greater rectal temperature depression. (Author).