Study of personal thermoregulatory responses after environmental cold step-change for group classification

Personalized regulation of the human thermal environment can save over 30% of energy consumption while maintaining thermal comfort. To realize efficient guidance to a personally suitable thermal environment, identification of the personal thermoregulatory features is necessary. This study provides a new method for classifying individuals according to their physiological thermoregulatory responses after a cold step-change. A series of experiments was conducted to investigate the individual differences in thermal responses. Three typical patterns of the finger-arm temperature gradient curve are summarized corresponding to vasomotor activities in the exposed areas, based on which the subjects are divided into three groups. Subjects in different groups show significant discrepancies in both physiological and perceptive responses after the cold step-change. Further experiments in various step-change conditions also show potential of this group classification in distinguishing people with different thermal features. The initial finger-arm temperature gradient can classify subjects with an accuracy higher than 60%, which can be increased with longer measurement duration. The proposed method can promote both thermal comfort and energy saving by facilitating personal thermal management, and practical applications of our results are encouraged to benefit not only intelligent indoor environment control but also personal health monitoring. •Three typical responses under cold step-change conditions was found.•Finger-arm temperature difference is promising in representing thermal requirements.•A method is proposed to classify individual thermal requirements.