To the editor: We read with interest the article in the June 1979 issue by Shapiro and associates (1) concerning heat intolerance in former heat-stroke patients. The significantly lower oxygen consumption in people with previous heat stroke may be related to their inability to increase cardiac output in response to an acute heat stress. An increase in cardiac output is necessary to dissipate a heat load imposed by increased environmental temperature (2). Therefore, it is not surprising that certain patients who develop heat stroke have an inappropriately low cardiac output despite severe heat stress (3).
We take exception with the