If you do end up in cold water due to an accident or emergency situation what is the most important thing you should do to stay warm?

If you find yourself in cold water, the most important action is to minimize heat loss. Try to keep your head above water and huddle your arms close to your body to conserve heat. If possible, adopt the fetal position to reduce exposure and retain body warmth. Additionally, if you're with others, group together to share body heat.