Is palmar and plantar sweating thermoregulatory?

We tested the hypothesis that palmar and plantar sweating has a thermoregulatory role and is mediated by the same thermoregulatory mechanisms that control sweating in the rest of the body surface. In a series of empirical tests involving 34 participants (five of whom exhibited palmar hyperhydrosis), the effect of high environmental temperature on sweating was examined. Wilcott's finding, that effects at the palm are of considerable magnitude, was confirmed only in subjects who were in a state of excitement. In relaxed subjects, the effects of high environmental temperature on palmar and plantar sweating was negligible. We conclude that the palms and soles do not directly participate in thermoregulation.