Hybrid cooling clothing to improve thermal comfort of office workers in a hot indoor environment

The study aimed to examine the effect of a hybrid personal cooling garment (PCG) on improvement of thermal comfort of office workers in a hot indoor environment. Eleven male subjects underwent two 90-min trials with one in PCG (i.e., with the hybrid personal cooling garment) and another with no cooling (i.e., CON). The trials were performed in a climate chamber with an air temperature of 34.0 ± 0.5 °C, relative humidity of 65 ± 5% and an air velocity of 0.15 ± 0.05 m/s. It was found that the hybrid PCG could remarkably improve the whole-body thermal sensations (TSs), skin wetness sensations (WSs) and comfort sensations (CSs) during most of time of the trials compared with CON (i.e., from the 10th min to the 40th min and from the 70th min to the 80th min for TSs, from the 10th min and the 20th min to the end of the test for WSs and CSs, respectively) (p < 0.05). The upper-body and lower-body TSs, WSs and CSs were all significantly improved in PCG from the 10th min to the end of the test (p < 0.05). In addition, mean skin temperatures and the total sweat production were also significantly reduced in PCG (p < 0.05). In summary, the hybrid PCG was highly anticipated to improve thermal comfort of office workers while doing office work in the studied hot and moderate humid indoor environment.