The main ways to prevent hypothermia caused by ice-water immersion are to use life-saving equipment reasonably, reduce activities in water, keep body and spirit quiet, and do everything possible to prevent or reduce the loss of body heat. Lifesaving equipment mainly consists of floating tools, such as life vest, lifeboat and anti-immersion suit, in order to avoid direct contact with cold water.
1. Wearing anti-immersion clothing
Air Forces of all countries have their own anti-immersion clothes, which have good waterproof and warm-keeping functions.
For the general maritime distress, if you put on thicker clothes before launching, you can prolong the survival time of cold water immersion, and you'd better put on waterproof clothes. Gloves and shoes must be worn if the water temperature is below 10 degrees Celsius to minimize heat loss.
2. Keep quiet
Those who fall into cold water should use life vest or catch the floating objects of sunken ship and float as quietly as possible. The discomfort in entering the cold water will soon ease. Swimming can only be considered when there is no life vest, no sunken boat floats, or when you have to leave the sinking vessel immediately, or when you are close to the coast or salvage vessel. Otherwise, even if you are skilled in swimming, you can only swim a short distance in cold water. In 10 C water, people with good physical strength can swim 1 - 2 kilometers; it is very difficult for ordinary people to swim 100 meters.
3. Protecting the head and taking certain postures to slow down body heat loss
After entering the water, head and neck should be avoided immersing in cold water as far as possible, and the flying cap or helmet should not be removed. Head and hand protection is very important. In order to reduce the surface area of the body contacted by water, especially to maintain several parts of high heat dissipation, i.e. the viscera, groin and chest, the posture of crossing hands in front of the chest and flexing legs to the abdomen should be taken in water. If there are several people together, you can pull up your arms and squeeze your body together to keep body heat.