DURING the past thirty years a large number of observations have been made upon the effect of heat on the human body. A summary of these up to the year 1927 is given by Bazett . The great majority of these have been either acute experiments under very severe conditions, or observations upon the work capacity of man under more moderate conditions. Very few investigations seem to have been made upon the resting subject under conditions prevailing in tropical zones, yet it is only by such observations that one can separate the effects of heat from those of the numerous other disturbing factors also occurring in tropical zones. Only by such experiments also can one delimit the "immediate effects" of these environments and thus be in a position to distinguish between the phenomena of the "period of adaptation" and those of the fully "acclimatized state".
D. H. Lee, A. G. Mulder
The Journal of Physiology