For a long time, the management targets for treatment of severe brain injury have been misunderstood. There is no doubt of the effectiveness of hypothermia treatment for ischemic brain insults in animal studies, as described in chapter 1. However, in clinical studies, the effects of hypothermia were dissimilar to those observed in previous animal studies. Essentially, the results of hypothermia treatment in experimental animal studies and in clinical results are different. The reason for this difference is very simple: the brain injury mechanisms in experimental animal models and in severely traumatized brain-injured patients are different.