VIII. HYPOTHERMIA
Prolonged exposure to cold water causes a condition known as hypothermia - a substantial loss of body heat, which leads to exhaustion and unconsciousness. Most drowning victims first suffer from hypothermia. The following chart shows the effects of hypothermia:
HOW HYPOTHERMIA AFFECTS MOST ADULTS
Water Temperature
º C | º (F) |
0.3(32.5)
0.3TO 4 (32.5 to 40)
4 TO 10 | (40 to 50) |
10 TO 16 | (50 to 60) |
16 TO 21 | (60 to 70) |
21 TO 27 | (70 to 80) |
Over 27 | (Over 80) |
Exhaustion or
Unconsciousness UNDER 15 MIN 15 TO 30 MIN 30 TO 60 MIN 1 TO 2 HOURS 2 TO 7 HOURS 2 TO 12 HOURS INDEFINITE
Expected Time
of Survival
UNDER 15 TO 45 MIN
30 TO 90 MIN
1 TO 3 HOURS
1 TO 6 HOURS
2 TO 40 HOURS
3 HOURS TO INDEFINITE
INDEFINITE
PFDs can increase survival time because they allow you to float without using energy treading water and because of their insulating properties. Naturally, the warmer the water, the less insulation you will require. When operating in cold waters [below 60º F(15.6º C)] you should consider using a coat or jacket style PFD or a Type V Thermal Protective PFD as they cover more of the body than the vest or belt style PFDs.
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