[Diurnal rhythm of human body temperature during antiorthostasis]

Circadian rhythms of the oral temperature were studied in three male test subjects kept for 7 days in a head-down position at -8 degrees. As compared to the controls (kept in a hospital for 3 days) the test subjects showed a statistically significant temperature increase (by 0.22 degrees C on the average) during circadian minimum points that occurred at night and a decrease of the daily temperature rhythm amplitude (by 0.20 degrees on the average). It is emphasized that study of human responses to various stress-agents should include monitoring of circadian rhythms of various parameters.