Abstract: A method for extracorporeal blood heating to effect whole body hyperthermia, which utilizes a hemodialyzer with a sorbent suspension in the dialysate, a blood pump and a heat exchanger--in addition to various probes and catheters and heated anterior and posterior blankets for the patient--to effect extracorporeal treatment without adverse effect on blood physiology and without the need for general anesthesia. Blood returning to the body is heated to at least about 46.degree. C. Incorporation of hemodialysis into the blood heating treatment solves at once several problems which plagued prior art hyperthermia techniques: it rectifies any imbalances of sodium, potassium, magnesium, bicarbonate or phosphate, and may remove toxins incident to necrosis of tumors and virally infected cells. Hyperthermia protocols with sorbent--based dialysis of blood thus avoid the various serious side effects which complicated--even to the point of death--the hyperthermia treatments known from the past.