The technique will initially be used on 10 patients whose wounds would otherwise be lethal in an attempt to buy the surgeons some time. It works, as suggested by science fiction, by cooling the body -- but not by applying an external temperature change.
Instead, a team of surgeons will remove all of the patient's blood, replacing it with a cold saline solution. This will cool the body, slowing its functions to a halt and reducing the need for oxygen. Effects similar to this have been seen in accidents: Swedish Anna Bågenholm survived trapped under a layer of ice in freezing water for 80 minutes in a skiing accident; Japanese Mitsutaka Uchikoshi survived 24 days without food or water by entering a state of hypothermic hibernation.