Experimental study on thermo-physiological differences between children and adults during indoor sedentary conditions

Previous research has shown that children prefer cooler environments and have lower thermal sensitivity than adults. This disparity may be attributed to physiological differences between these age groups. However, studies are scarce that specifically measure children's physiological parameters. In this study, we measured the physiological parameters of children aged 6–9 years and their parents, concurrently collecting their thermal comfort votes. Measured physiological parameters include metabolic rate, blood flow, body composition, core temperature, blood oxygen, heart rate, skinfold thickness, and skin temperature. We found that the average metabolic rate of the measured children was 1.20 met, 39% higher than the measured adults who had their average metabolic rate as 0.86 met. Children consistently exhibited higher metabolic rates than their own parents. Children were observed to have less body fat and thinner skin folds compared to adults. Additionally, children exhibited higher skin temperatures in core areas, elevated heart rates, and quicker recovery of skin blood flow and local skin temperature after experiencing cold exposure on hand compared to adults. These characteristics reveal children's superior thermoregulatory abilities, explaining their preference for cooler environments and reduced thermal sensitivity. Besides, no gender difference was observed in the thermal physiology of the measured children. All of the distinctive thermal physiological traits of children underscore the necessity of specific criteria for evaluating the thermal comfort of children.