Therapeutic hypothermia improves neurologic outcome in patients after cardiopulmonary resuscitation (CPR) because of cardiac arrest. In the present study patients will be cooled to 33 degree Celsius after CPR for 24h. To avoid shivering patients will be analgosedated and medically paralysed. Analgosedation and relaxation have already shown to reduce oxygen consumption up to 20 % in critically ill patients.