Therapeutic hypothermia (32 - 35°C) attenuates reperfusion injury and therefore reduces infarct size in a variety of animal models of acute myocardial infarction (AMI), if provided before reperfusion. In human studies this reduction has not been confirmed so far, probably due to the fact that systemic cooling is slow in reducing temperature and therefore target temperature was not reached in time in a substantial number of patients or not reached at all. Furthermore, systemic cooling has side effects such as severe shivering, volume overload and an enhanced adrenergic state. However, subgroups of patients in all randomized clinical trials with anterior myocardial infarction who reached target temperature before reperfusion did show a reduction in infarct size.