Taking thermal regulation models from the lab to the world:Are current views ready for the challenge?

Current thermoregulation and coupled thermal sensation models are mostly based on and validate for laboratory settings. In order to investigate the performance of a thermoregulation model in practical settings, this study collects data in experiments undertaken in everyday situations from sitting in the office (1 met) to walking outdoors (2.8-2.9 met). Also, the clothing consists of realistic outfits with a variation in upper body clothing insulation (0.55-1.14 clo). Six combinations of activity levels and insulation values are followed by 3 male and 2 female individuals. Overall, the computed mean skin temperature is in good agreement with measured data. For averaged distal skin temperature (hand and foot) high variations are found. The temperature deviation might be caused by either false heat delivery via skin blood flow or misestimated heat losses. For further research it is suggested to measure skin blood flow in similar experiments. A difference between male and female subjects is seen especially for proximal skin temperatures (thorax and abdomen). Therefore, physiological differences between males and females have to be incorporated in the model. Furthermore, clothing insulation has an impact on the temperature differences of the data and hence, also needs revision especially with regard to local insulation values.