Idiopathic explosive malignant hyperthermia, which occurs after anesthesia is given, is a syndrome of increasing prevalence. It is a separate entity from the "postoperative heatstroke" reported in days prior to temperature and humidity control of operating rooms. Reviews of 40 cases from the literature and the authors' own experience reveal a 73% mortality in an otherwise healthy and young ([unk] 21 years) age group. The only reasonable explanation of the etiology appears to be an uncoupling of oxidative phosphorylation. Treatment even with early diagnosis is difficult.