Prediction chart of thermal sensation levels derived from a sweat pore system model.

Because of the half-way wet-and-dry skin surface, it is very difficult to analyze and predict the heat loss by sweat evaporation It is significant that neither wetness nor wet area ratio can be a universal index under the influences of different air current, the state of being clothed making them less useful. Therefore, in an attempt to predict the dynamic thermal sensation levels by means of the simulation method, a sub-skin wet layer and a sweat pore system regulating sweat evaporation were assumed. It was shown that it is possible to indicate the probable values of moisture permeability through the skin or clothing. On the basis of such a thermal systems approach, conditions of the environment, including radiant and ambient air temperature, humidity, and air movement and those of the human bodyworking and wearing clothes could be related to each other as shown by several examples. Then the scaling method of thermal sensation levels were proposed. Finally, the sub-skin heat capacities were discussed according to the step response simulation using the results of cold shock tests.