Several reports during the past 15 years have described hyponatremia as a result of excessive water intake by athletes during endurance races. The high rates of fluid consumption have been attributed to the desire of athletes to prevent heat injury. The military has adopted guidelines for programmed drinking to maintain performance and minimize the risk of heat casualties. As military personnel increase their fluid intake, their risk of hyponatremia as a result of water overload increases. A potentially life-threatening complication is acute water intoxication. We report the first known death of an Army basic trainee as a result of acute water intoxication. The misinterpretation of his symptoms as those of dehydration and heat injury led to continued efforts at oral hydration until catastrophic cerebral and pulmonary edema developed.