Heat Tolerance of Bantu and Pygmoid Groups of the Zaire River Basin

Samples of Bantu Ntomha and Pygmoid Batwa men were subjected to a heat acclimatization test and a test of tolerance to humid heat stress. In the acclimatization test both groups walked together at 5 km/hr in the afternoon sun. In the second test subjects were exposed to heat by means of a hot water bath. In both tests of heat tolerance the Batwa appeared to be more stressed on the basis of body core temperature and heart rate. The results suggest that small bodied populations may have a lower heat tolerance than larger bodied populations under some environmental conditions