transient foot cooling was perceived as comfortable when the whole body was warm, and perceived as uncomfortable when the whole body was cold, which is in good agreement with the results obtained in the present study (see Fig. 9). Zhang also found that the ‘‘Very comfortable’’ vote occurred in the dynamic responses of foot thermal comfort when the whole body was warm or cold and the foot was cooled or warmed in the opposite direction to relieve discomfort. In the present study no ‘‘Very comfortable’’ vote occurred in the dynamic responses mainly because that whole body thermal comfort was reported in the present experiment, which is proposed by Zhang [18] to be the average of the minimum and maximum local thermal comfort votes.
Ebbecke [22] was first to distinguish between temperature sensations and thermal comfort by their related physiological responses and mentioned that thermal sensations were assumed to be correlated with the activity of cutaneous thermoreceptors, whereas thermal comfort was assumed to be depended on thermoregulatory reflexes originating from the heat regulation center. The assumption has been confirmed experimentally by Gagge et al. [7] and Hardy [23] who used separate scales for comfort and sensation, respectively. The experimental results obtained in the present study are in good agreement with the assumption as well. Whole body thermal sensation is the integrated response of signals discharged from the cutaneous thermoreceptors of all body segments; however, whole body thermal comfort is related to the thermoregulatory reactions of all body segments, which may be affected by thermal storage or thermal non-uniformity of human body in non-steady or non-uniform conditions.