The invention relates to a dialysis device having an extracorporeal blood system, a dialyzing fluid system, a dialyzer and a control unit, wherein the dialysis device has a heating mechanism for heating the blood in the extracorporeal blood system before entry into the dialyzer or in the dialyzer as well as a cooling mechanism for cooling the blood in the extracorporeal blood system after exiting the dialyzer and wherein the control unit is configured such that the blood is heated before entry into the dialyzer or in the dialyzer to a dialysis temperature which is above the body temperature of the patient and is cooled back to the body temperature of the patient after exiting the dialyzer.
