This Boat-Ed safety course video discusses what to do if you fall overboard and the dangers of cold water immersion. It also covers what to do to prevent hypothermia while in the water and waiting for help.
During cold weather a lot of people enjoy hunting, fishing and other activities but it's during this time that falling into the water poses a serious threat.
When you first enter the water the initial cold shock can cause involuntary gasping, hyperventilation and panic. Try to control your breathing. Hold on to something if you can and stay still until your breathing settles down. Focus on floating with your head above water until the cold shock passes.
In cold water you can lose dexterity in 10 to 15 minutes so make sure your PFD is fastened securely. Try to re-board your boat even if it's swamped or capsized. Keep as much of your body out of the water as possible.
Don't take your clothes off unless absolutely necessary. Remember, clothes trap heat and can help you float. If you can't re-board, a PFD will allow you to stay afloat and it will also help you to insulate your body. Be sure to keep your head and neck out of the water.