Study on human thermophysiology and severe-cold protection during physical activity in simulated high-altitude environments.

The unique climate of plateau regions increases the risk of cold-related conditions, such as hypothermia and frostbite. Therefore, it is essential to study and improve severe-cold protective equipment for use in these environments. This research involved an experiment simulating a plateau at an altitude of 4,500 m, with an ambient temperature of -9℃ and 23℃. Sixteen healthy male participants performed two types of physical activities-weighted hiking and heavy lifting-while thermophysiological and subjective thermal responses were recorded, including local skin temperature and thermal sensation. Statistical analysis revealed that different physical activities and environmental temperatures in plateau environments significantly influence human thermophysiology. During hiking, the back and shoulders exhibited weaker correlations with other body segments, likely due to insulation effects of the carried backpack. During lifting, weak correlations were primarily observed in the upper and lower limbs, which were more actively engaged. Time-series analysis further showed that skin temperatures in the head, chest, shoulders, armpits, forearms, thighs, and feet remained relatively stable, while the back, pelvis, hands, and calves displayed consistent declines, indicating insufficient insulation in these areas. Thermal perception results aligned with objective measurements. Hiking under severe-cold conditions was perceived as more thermally comfortable, whereas lifting induced colder sensations in the extremities and a warmer feeling in the torso. These findings provide an important reference for the targeted design of cold-protective equipment and offer practical insights for improving thermal safet in high-altitude, low-temperature environments.