Hypothermia

Also: exposure

A fall in the body's core temperature below 35 °C. Often blamed for deaths it did not cause, and often present in deaths blamed on something else.

Questions this entry answers

  • What is hypothermia?
  • How fast does hypothermia set in in cold water?
  • Is hypothermia the main cause of death in shipwrecks?

Definition

Hypothermia is a core body temperature below 35 °C (95 °F). It is a measurement, not a description of being cold. A person can be freezing, shaking and in danger without yet being hypothermic.

Historical context

Exposure has killed soldiers on winter marches, refugees on open roads and survivors in lifeboats in every period this archive covers. For most of history it had no clinical definition; people described men who "died of the cold". The modern definition lets us separate hypothermia from the other ways cold kills, especially in water.

How it worked

The body defends its core. Blood is drawn away from the skin and limbs, and shivering generates heat. As the core cools further, shivering can stop, thinking slows and judgement fails. In water, the body loses heat far faster than in air at the same temperature, but even there clinical hypothermia usually takes twenty to thirty minutes or more to develop. Other stages of cold-water immersion often kill first.

What it meant for the patient, the soldier, the civilian

The danger of hypothermia is that it takes away the ability to save yourself before it takes away consciousness. Hands that cannot work a buckle, a mind that stops recognising danger. The person who most needs to act is the one least able to.

It also matters how we describe the dead. Saying everyone in a cold-water disaster "died of hypothermia" hides the first minutes: the gasp, the drowning, the hands that would not close on a rope.

Examples from history

  • The Wilhelm Gustloff, 1945. Survivors describe air temperatures of −10 to −18 °C. One research summary states that most deaths were from hypothermia; our own research on cold-water immersion found that claim too broad, and the episode says only that people died in the water.

Sources

Sources listed
2
Checked against the source
0
Not yet checked
2

Scholarly secondary source

  1. Tipton et al. (2017). "Cold water immersion: kill or cure?" Experimental Physiology 102, 1335–1355. View source

    Not yet checked against the source

Reference work

  1. U.S. Coast Guard, National Search and Rescue Supplement, §3.7.2, "Four Stages of Cold Water Immersion."

    Not yet checked against the source

Know a better source or see an error? Send a correction.