Physiological and perceptual responses of exposure to different thermal environments at low pressure (61.6 kPa)

In aerospace and military activities, people tend to encounter hypobaric and hypoxic extreme environments caused by the high-altitude, which can lead to physiological and perceptual changes of the human body, thus affecting work efficiency and health. In this study, ambient temperature is set at 21 °C, 26 °C, 30 °C, and altitude is set at 4000 m, with humidity of 40% and air velocity of less than 0.3 m/s. Besides, 13 healthy subjects were recruited to continuously measure their physiological parameters, including axillary temperature, local skin temperature, blood oxygen saturation, heart rate, and blood pressure, and the subjective parameters of overall and local thermal sensation. The main results are as follows: At 21 °C, the axillary temperature declined slightly over time. Also, there was a linear correlation between local skin temperature and thermal sensation. The heart rate and sweating rate under 30 °C were higher than under other conditions(P