Heat stroke is the outcome of impaired heat dissipation which is aggravated by hot and humid environmental conditions. The very young and debilitated on the one hand and healthy individuals under considerable physical stress on the other are vulnerable to heat stroke. Post-mortem findings will depend on the time lapse between the stroke event and death. We report on the deaths resulting from heat stroke in a 12-month-old baby and three 19-year-old soldiers. Reconstruction of the environmental conditions enables elucidation of the circumstances that precipitated exogenous hyperpyrexia. The Discomfort Index presents reliable criteria for the assessment of heat load: values above 28 units are considered as severe heat load and are life threatening. Awareness of the hazards related to severe heat load on the body is helpful in preventing avoidable calamities.