Ethnic differences in thermoregulation: Genotypic versus phenotypic heat adaptation

Abstract This paper focusses upon evidence of thermoregulatory differences among racially divergent humans. Thermal habituation is a central theme, explored first in the cold, and then within hot environments. The thermoeffector of primary interest is the eccrine sweat gland. It is hypothesised, with supporting evidence discussed, that the lower sweat secretion observed in indigenes from hot regions represents a form of thermoregulatory habituation. Finally, elements of experimental design are discussed for future research in this field.