Human body can adjust heat loss by vasoconstriction, vasodilatation, and
other methods. The purpose of this research is to investigate whether the
thermal resistance of skin reflects vasoconstriction and vasodilatation.
For this aim, the ambient temperature was controlled as 18.1, 21.6, 24.9,
27, and 30.5?C, respectively. In each temperature, the skin temperature
and heat flux in the forearm were recorded. Based on tested data, the
thermal resistance was calculated by a common method. The results showed
that the thermal resistance at low temperature was less than that at high
temperature, which was contrary to the rule of vasoconstriction and
vasodilatation. So a new formula for thermal resistance was presented based
on skin diffusion, sweat evaporation, and mass transformation. The results
showed that the new method could predict vasoconstriction and
vasodilatation. The revised equation is a useful index for physiological
thermoregulation.