It is well known that hyperthermia above 41°C rarely occures in ordinary pysiological state and that, the course of patient will be always grave with fatal outcome under high body temperature exceeding 42°C
During induced-hyperthermia above 42°C, animal (dog or monkey) evidenced respiratory depression, insufficiency of cardiovascular system, metabolic and respiratory acidosis, elevation of serum enzymes, lacticidemia and hyperkalemia.
In clinical investigations of fatal cases with hyperthermia (Malignant hyperthermia and heatstroke), thrombcytopenia and disturbances of clotting factors were observed, and autopsy findings consisted of widespread haemorrhages, congestion and cellular degeneration in numerous organs, oedema in brain and lung, and nerosis in brain and kidney.
These investigations revealed that hyperthermia exceeding about 42°C involving all organs caused multiple organ failure and irreversible changes in tissues.
So, it is suggested that body temperature of about 42°C is critical temperature for living body under hyperthermia.
These organ failure and tissue damage occuring in fatal hyperthermia might be explained by heat-induced cellular damage that, under high temperature, fat and protein in the cell undergo irreversible conformational changes.
