Therapeutic hypothermia also is effective in reducing reperfusion injury. Several inflammatory immune responses occur during reperfusion to tissues after an ischemic event such as a cardiac arrest. Oxidative stress causes damage by releasing free radicals, and the inflammatory response can lead to increased intracranial pressure (ICP). An increase in ICP can lead to additional cellular injury and, at times, cell death. Finally,therapeutic hypothermia decreases overall cellular demand for oxygen by reducing metabolism. This further decreases the chain of events leading to reperfusion injuries