Glossary
Cold incapacitation
Loss of muscle control in the arms and legs from cold water, which makes swimming or holding on impossible.
Cold incapacitation is the loss of strength and muscle control in your arms, legs, hands and feet as cold water cools them. The National Weather Service (opens in a new tab) says it can be felt within seconds of entering cold water, and grows worse the longer you are in and the colder the water is. Signs include weakness, exhaustion and being unable to control your fingers, hands, arms or legs.
Why it matters: it usually arrives long before hypothermia. As your limbs stop working, swimming, grabbing a rope or climbing back into a boat becomes impossible. The NWS says that losing the muscle control needed to keep your head above water, without a life jacket, makes drowning inevitable. The National Center for Cold Water Safety (opens in a new tab) notes that cold incapacitation can occur within 2 to 30 minutes, and within 2 to 10 minutes in water near freezing.
The practical lessons:
- wear a life jacket before you go out, so you float even when your limbs give out;
- do the most important things, such as getting onto the boat or ice, first;
- dress for the water temperature, not the air.
See what to do if you fall into cold water and cold water shock.
What you can do today: keep a life jacket on whenever you are on cold water, even close to shore.