Summary
When we’re in cold water, we lose heat. The rate at which we lose heat is primarily determined by the water temperature, how hard we’re working, and our body size and shape. Getting too cold can lead to swim failure and hypothermia. Training and increasing body fat can help improve our tolerance to cold water, but remember there are negatives to putting on weight. The body continues to cool after exiting the water in a process known as afterdrop. Improving our ability to swim in cold water trains us to tolerate discomfort.