Most risks are preventable with the use of exposure suits. Wet-suits are typically pre-warmed with warm water in order to keep divers warm throughout a frozen competition. Three finger mitts are usually recommended. Smaller body parts such as fingers, toes, ears, and the nose are at the highest risk for frostbite and are the most vital to keep covered and warmed. Divers are also warned against heavy exercise after resurfacing from the ice. Decompression sickness has not been studied enough for extreme cold and any measures taken to prevent causing sickness is recommended.