- Heat stroke is a life-threatening syndrome of multi-organ dysfunction caused by elevated body temperature. It may result from failure of the thermoregulatory mechanisms or from inadequate heat dissipation and affects members of several risk groups. A number of authors reported cardiac involvement in heat stroke, but heart failure rarely has been documented. We report the cases of two heat stroke victims, one of whom developed pulmonary edema and the other, peripheral edema. In both, RVG demonstrated dilatation and diffuse hypokinesis of the right ventricle, which persisted for several weeks. We conclude that the heart may be involved in heat stroke and that heart failure is a potential complication of the syndrome that can have a prolonged subclinical course. Fluid replacement in heat stroke should be done under careful observation, which may be facilitated by noninvasive assessment of cardiac function.