Chapter 13 · Sea, lakes, and rivers
Falling into cold water: the 1-10-1 rule
Water pulls heat from the body about 25 times faster than air. The U.S. Coast Guard considers water below 59 °F (15 °C) critical, but cold shock can occur in warmer water if you fall in suddenly. What kills first is not hypothermia but the gasp reflex and the loss of strength in your arms and legs. The Canadian Safe Boating Council sums it up in the 1-10-1 rule:
| Approximate time | What happens | What to do |
|---|---|---|
| 1 minute | Cold shock: involuntary gasping, rapid breathing, panic. If you inhale water at this moment, you can drown. | Keep your head out, mouth closed, and focus on controlling your breathing. Do not try to swim yet. The life jacket keeps you afloat. |
| 10 minutes | Loss of useful use of your hands, arms, and legs. After that you will no longer be able to grab on to or climb onto anything. | Use these minutes to get out of the water: onto the overturned boat, onto a nearby shore, or onto something that floats. If you cannot, adopt the HELP posture. |
| 1 hour | Hypothermia leading to unconsciousness. Without a life jacket, you drown when you lose consciousness. | Conserve heat, stay still, signal. With a life jacket you have more time to be found. |
- Do not take off your clothes or shoes. They trap water that your body warms and they protect you.
- Do not swim aimlessly. Swimming cools you faster. Swim only if a safe place is very close.
- Climb onto the overturned boat or whatever floats: getting your body out of the water, even partly, greatly reduces heat loss.
- When you are rescued, a cold-water victim must be handled gently and kept horizontal; they can faint or have heart problems when pulled out (chapter 14).
