Therapeutic hypothermia following cardiac arrest was a strategy to improve neurological outcomes first explored in 2002 following the publication of the publication of a trial by Bernard and colleagues in the NEJM. The theory was that metabolic demand slowed when the patient was placed in a hypothermic state. This would improve neurologic outcomes by reducing cerebral oxygen demand. It’s similar to the practice of cooling the patient during deep hypothermic circulatory arrest in the operating room for complex cardiac surgeries such as repair of the aortic arch.
The downside is, there are a number of major consequences and potential complications from hypothermia, as anyone who has treated environmental injuries associated with prolonged cold exposure can tell you. In the intervening 20 years since the initial Bernard study, a number of other studies have been published showing the benefit of cooling, but more than likely, no need for true hypothermia.
Bottom line, it seems that prevention of hyperthermia is probably just as beneficial and hypothermia, with far fewer deleterious effects. The University of Kentucky ICU Pharmacy recently did a great tweetorial summarizing the data surrounding hypothermia. Check it out for more details.