Autopsy reports at the Forensic Science Centre, Adelaide, South Australia, were reviewed for the 8 years from January 1991 to December 1998 for cases with unusual features in which deaths had been attributed to exposure to high environmental temperatures. Amphetamine-related hyperpyrexial deaths, anesthetic deaths caused by malignant hyperpyrexia, deaths of elderly incapacitated individuals during heat waves, and deaths of children trapped in the back of cars were excluded from the study. In 9 cases, where heat-related deaths had occurred (age range 21 to 77 years; M:F = 8:1). Predisposing factors included lack of familiarity with Australian environmental conditions, excessive clothing, prolonged sun exposure, acute alcohol intoxication, obesity, benztropine and trifluoperazine medication, and underlying dementia, alcoholic liver disease, and possibly epilepsy.