While cardiopulmonary symptoms are common in patients undergoing classical or, due to physical exercise, exertional heat stroke, the failure of other organs is a rarely described phenomenon. Here we present two cases of acute hepatic failure, one due to classic heat shock, while the other occurred while the patient was doing a marathon-type running. Both cases presented with very high transaminases and significantly elevated international normalized ratio (INR). No other causes for liver failure could be identified but physical exhaustion and hyperthermia. While cardiopulmonary symptoms are common in patients undergoing classical or, due to physical exercise, exertional heat stroke, the failure of other organs is a very described phenomenon. other occurred while the patient was doing a marathon-type running. Both cases presented with very high transaminases and significantly elevated international normalized ratio (INR). No other causes for liver failure could be identified but physical exhaustion and hyperthermia.