Effects of Different Humidity Levels on the Human Body in a High-Temperature Environment at High Altitude

With societal progress, occupational safety has become a growing concern, particularly in high-altitude, high-temperature, and high-humidity environments, which are considered the most extreme and have garnered widespread attention. To improve existing protective measures and reference standards for specialized occupations and reduce harm to the human body, this study investigates the effects of different humidity levels on body surface temperature and humidity in high-altitude, high-temperature environments, aiming to explore human tolerance. Eight subjects (four males and four females) sat quietly for forty minutes in a high-altitude, high-temperature chamber with humidity levels of 30% and 60%, during which body surface temperature and humidity at seven different body sites were recorded using button temperature sensors. Additionally, the subjects filled out subjective scales and recorded their weight. Statistical analysis revealed that the temperature and humidity at different body sites varied over time under the two humidity conditions. Notably, changes in body surface humidity were more significantly influenced by body site, whereas temperature changes were less affected. Furthermore, gender differences were observed, with females exhibiting higher and more fluctuating body surface temperatures than males in both humidity conditions. The trends in body surface humidity changes also differed, and in some cases, were even opposite between the two genders. Based on the results of this small-sample experiment, the findings suggest that, when designing protective clothing, different fabrics with varying breathability and sweat absorption properties should be used for different body areas, and gender differences should also be considered.