Circadian Rhythm of Core Body Temperature (Part II): Hyperbaric Environment Influence on Circadian Rhythm of Core Body Temperature

The aim of this study was to analyse dynamic fluctuations in the circadian rhythm of the core body temperature in healthy adults exposed to conditions in a hyperbaric chamber, using fully objective-telemetric measurement methods. The study group consisted of 13 healthy males (age 32±6.4 years, height 1.85±0.1 m, body weight 84.00±6.3 kg; BMI 24.7±1.2 kg/m²). The core body temperature (CBT) was measured with the Vital Sense telemetry system. The volunteers were placed in a hyperbaric chamber, exposed to compression of 400 kPa, with the exposure plateau of approx. 30 minutes, followed by gradual decompression. The mean core temperature was 36.71°C when registered within 10 minutes before the exposure, 37.20°C during the exposure, 37.27°C one hour after the exposure, 37.36°C 2 hours after the exposure, and 37.42°C three hours after the exposure. The conducted observations show that one-hour stay in a hyperbaric chamber at a depth of 30 m results in an increase in the body temperature, particularly significant after the exposure ends, and maintained for at least 3 hours after the exposure.