Experimental study on a novel phase change cooling garment to improve the thermal comfort of live-line workers

The study investigated the impact of a phase change cooling garment on the thermal comfort of live-line workers in humid and hot environments (38 °C, 75 % RH). A novel phase change cooling garment (C1), weighing 3.21 kg, was developed based on ergonomic design. The cooling effectiveness of C1 was assessed through evaluations conducted in an artificial climate chamber and field experiments. These evaluations measured physiological parameters such as heart rate, blood pressure, blood oxygen saturation, skin temperature, and core temperature, along with subjective questionnaires that covered overall and local thermal sensation, thermal comfort, and moisture sensation. The results demonstrated that C1 effectively reduced both the average and local skin temperatures in the cooled areas. Specifically, the average skin temperature decreased by approximately 2.4 °C, head skin temperature by about 1.2 °C, torso skin temperature by about 5.7 °C, and neck skin temperature by about 5.9 °C. Core temperature showed a reduction of approximately 0.4 °C. The use of C1 had minimal impact on other physiological parameters measured. Additionally, C1 significantly lowered subjective thermal sensation scores, with the overall thermal sensation vote (TSV) decreasing by 2.65 levels and the overall thermal comfort vote (TCV) decreasing by 1.7 levels. The overall heat stress level was reduced from severe to mild. Compared to other cooling garments, C1 exhibited superior performance in terms of thermal comfort. The findings provide valuable guidance for the design of personal phase change cooling garments, contributing to enhanced safety and comfort for live-line workers in humid and hot environments.