Each year 4,000–9,000 people die in the USA from hyperthermia-related crises, such as heat stroke and febrile convulsions. In most of these cases, variable combinations of hot environment, physical exercise, dehydration, and infection can be identified. Heat stroke is a complex clinical picture with poorly understood pathophysiology and unexplored resuscitation potentials. Protection of vital organs against hyperthermia is also important for cancer therapy.

This study (1978–1980) was aimed exclusively at the effects of controlled hyperthermia. In pilot experiments on lightly anesthetized dogs and rhesus monkeys, brain temperature was raised to 42°C for 1/2–1 hour by immersion heating. This was followed by cooling to normothermia. Partial recovery with a lucid period of 1 hour or longer was followed by diffuse gastrointestinal bleeding and irreversible shock in spite of standard life support measures.