Question: how does the body stay warm under water

Paul Higgins answered on 18 Nov 2012:

Your body generates heat in a few ways, such as through chemical reactions (when you eat your lunch and digest it), as well as through friction when you use your muscles. So when you are underwater, your body is still producing heat. If you swim really fast underwater, you will feel a lot warmer, because your muscles are working hard and heating up!