Skin temperature indexes to evaluate thermal sensation and cognitive performance in hot environments

With further study on human thermal comfort, the correlation between human thermal physiological parameters and thermal sensation in different environments has received increasing attention from many researchers. And the relationship between skin temperature and thermal sensation and cognitive performance is being further explored. In this study, the skin temperature indexes to evaluate thermal sensation and cognitive performance in hot environments were explored based on human objective responses (skin temperature, cognitive tests) and subjective assessments (thermal sensation) in climate chamber. The results showed that the CVs (coefficient of variation) and TDs (maximum temperature difference) of skin temperature were significantly higher during stage II(>30min) than during stage I(≤30min) (p < 0.05). The forehead and wrist were highly correlated with thermal sensation in stage I and stage II, respectively. Meanwhile forehead and wrist thermoneutral temperature ranges were 34.4 °C∼34.8 °C and 34.3 °C∼34.6 °C, respectively. Cognitive performance was highly correlated with skin temperature at the wrist during stage II (R = −0.96**). And the best performance was achieved when the TSV was approximately −0.008 and the wrist temperature was 34.5 °C. Overall, 34.5 °C was recommended for exposed areas such as the forehead and wrist to obtain best cognitive performance and thermal sensation.