Determination of heat loss from the feet and insulation of the footwear

This study compared the methods of determining the footwear insulation on human subjects and the thermal foot model. Another purpose was to find out minimal number of measurement points on human foot that is needed for insulation calculation. Bare foot was tested at three ambient temperatures on 6 subjects. Three types of footwear were tested on 2 subjects. The mean insulation for bare foot obtained on the subject and model were similar. The insulation of the warm footwear measured by the two methods was also similar. For thin footwear the insulation values from the subjects were higher than those from the thermal model. The differences could be related to an undefined physiological factors. Two points on foot can be enough to measure the insulation of footwear on human subjects (r=0.98). However, due to the big individual differences of humans, and good repeatability and simplicity of the thermal foot method, the latter should be preferred for testing.