The Facts on Hypothermia and Cold Weather
Cold water (less than 70° F) can lower your body temperature, causing hypothermia. If your body temperature drops too low, you may pass out and then drown. The human body cools 25 times faster in cold water than it does in air.
Water temperature, body size, body fat percentage and movement in the water each play a part in cold-water survival. Small people cool faster than large people; children cool faster than adults.
Lifejackets can help you survive cold water. They let you float without using energy while insulating your body from cold water. A snug-fitting lifejacket is better than a loose-fitting one. When you boat in cold water, use a flotation coat or flotation coverall. In cold water these are preferred to vests as they cover more of your body and help maintain your core body temperature.
How hypothermia affects most adults
|Water Temperature (Fahrenheit)||Exhaustion or Unconsciousness||Expected Time of Survival|
|32.5 degrees||Under 15 minutes||Under 15 to 45 minutes|
|32.5 to 40 degrees||15 to 30 minutes||30 to 90 minutes|
|40 to 50 degrees||30 to 60 minutes||1 to 3 hours|
|50 to 60 degrees||1 to 2 hours||1 to 6 hours|
|60 to 70 degrees||2 to 7 hours||2 to 4 hours|
|70 to 80 degrees||2 to 12 hours||3 hours to indefinite|
|Over 80 degrees||Indefinite||Indefinite|