Cold-water immersion is no joke. A prudent hunter plans for the worst. You need to get warm and dry as fast as possible. It’s a good idea to carry extra warm clothing you can change into, and some warm fluids in a thermos to warm you from the inside. If you don’t have that, remember there are four ways to get warm: Insulate, exercise, consume calories, or have a heat source. In a worst-case scenario, find some dry land to build a fire, dry your clothes, and get warm.