Hypothermia can kill. It most often afflicts people who have been shipwrecked or lost in the woods. It isn’t a treatment you would expect to receive in hospital. It is, however, becoming a common and useful method to prevent severe brain damage in patients that have suffered unconsciousness due a lack of oxygenated blood—such as those who have suffered a sudden cardiac arrest.

This article shall explore the what, when, why and how, of this (relatively) new therapy.

What

The term is not that common, but usually understood by the general public. It comes from hypo - meaning below, and the Greek thermē - for heat. It describes a normally dangerous situation where the body temperature is lower than normal. (There is also another very similar word hyperthermia, which has the same origins, except hyper means beyond, and describes higher than normal body temperature.)