The US Coast Guard explains which are the symptoms of hypothermia, highlighting that body heat can be lost 25x faster in cold water than in air.
USCG explains that frost nip, frost bite, and hypothermia are medical conditions associated with cold stress.
As shown in the picture above, the signs of hypothermia are:
- confusion
- shivering
- difficulty when speaking
- sleepiness
- stiff muscles.
In addition, the coast guard divides hypothermia in three parts:
#1 Mild hypothermia (98-90° F) which leads to shivering, lack of coordination, stumbling, fumbling hands, slurred speech, memory loss, pale, cold skin.
#2 Moderate hypothermia (90-86° F) that leads to shivering stops, unable to walk or stand, confused and irrational.
#3 Severe hypothermia (86-78° F) that shows severe muscle stiffness, very sleepy or unconscious, ice cold skin. Death is eminent.
Concerning death, the Marine Advisory Medical Service for Standard Club has provided a practical guide for Masters regarding the management of death at sea.
Following the severe, in some cases, symptoms of hypothermia, USCG provides some tips concerning preventative measures for cold stress in order to survive in cold water:
#1 Drink moderate amounts of water frequently.
#2 Avoid alcohol, certain medications and smoking to mitigate risk.
#3 Wear appropriate clothing:
- Cotton looses insulation when wet
- Wool retains insulation when wet
- Wear layers
- Outer layer to deflect wind,
- Middle layer (down, wool) to absorb sweat and provide insulation even when wet,
- Inner layer (cotton, synthetic weave) allow insulation/ventilation
- Wear cover/hat (60% of heat is lost though head)
- Wear insulated boots and full fingered gloves
- Loose clothing allows better ventilation
