Effects of body muscle and fat on differences in thermal preference

Although it has been shown that obese individuals have good cold tolerance due to the thermal insulation of the fat layer, some lean individuals also prefer cool environments. Here we systematically investigate the indicators of fat and muscle and consider their impacts on thermal preference. Combining the survey data on body mass index (BMI) and exercise, and the experimental data on tissue thicknesses, thermal sensation, thermal comfort, and skin temperature, we show that high fat or high muscle correlates positively with cool preference. In contrast, low fat or low muscle correlates with warm preference. Furthermore, participants of the same body size, one group of high muscle content (HM group) and another group of low muscle content (LM group), are enrolled in a thermal response experiment. Our results suggest that the HM group can accept lower temperatures than the LM group. The results can be used to explain the differences in thermal responses of occupants in the same environment.