Cold shock response

From Wikipedia, the free encyclopedia

Cold shock response is the physiological response of organisms to sudden cold, especially cold water.

[edit] Myth of sudden hypothermia

In humans, cold shock response is perhaps the most common cause of death from immersion in very cold water, such as by falling through thin ice. The cold water can cause heart attack (as cold blood from the extremities reaches the heart) and inspiration of water (and thus drowning) from hyperventilation. Some people, due to body type or mental conditioning, are much better able to survive swimming in very cold water.

Hypothermia from exposure to cold water is not as sudden as is often believed. A person who survives the initial minute of trauma (after falling into icy water), will typically survive for more than an hour provided they don't drown. However, the ability to do perform useful work (to save oneself) declines substantially after 10 minutes (as the body protectively cuts off blood flow to "non-essential" muscles).

[edit] Sources