Study on thermal comfort of low-sweat and high-sweat young men based on heart rate variability analysis under different clothing

Abstract

Thermal comfort is one of the most important factors affecting human performance. In recent years, the Low Frequency to High Frequency Ratio (LF/HF) index, which is obtained from the frequency analysis of heart rate variability, has been proposed as an accurate method for evaluating thermal comfort in different conditions. In this study, using LF/HF, the effect of sweating amount on thermal comfort under the influence of clothing characteristics was investigated. After a moderately heavy physical activity in the indoor situation and without good ventilation, skin temperature, electrocardiogram signal and a qualitative assessment of their thermal comfort were recorded in participants divided into two groups: low sweat and high sweat. The results of qualitative measurement and frequency analysis of thermal comfort were then discovered to have a significant correlation. According to findings, the low sweat group had less thermal comfort than the high sweat group (p < 0.05). The type of clothing was also found to have a significant effect on the thermal comfort sensation. Although the amount of sweating is an inherent feature of an individual, the feeling of thermal comfort can be improved (p < 0.05) by optimizing clothing characteristics for each group without spending more energy on cooling.