Two cases of serious hypothermia efficiently treated with Venous-Arterial Extracorporeal Membrane Oxygenation (the blood is pumped from the venous system to the arterial side) were presented. The warming process of the patient diagnosed with hypothermia (< 35°C) should begin as soon as possible. In cases where the body temperature is lower than 28°C a telephone consultation with the coordinator for extracorporeal deep hypothermia treatment is advised. The classification and treatment methods for hypothermia described below are based on the European Resuscitation Council and the American Heart Association Guidelines. This paper presents two clinical cases of patients with hypothermia subjected to ECMO treatment in the Anesthesiology and Intensive Care Clinic and the Cardiac Surgery Clinic of the Regional Hospital in Kielce.