First of all, you need to see under what conditions they freeze, after playing the game or after full warm-up training. At this time, the whole body has a lot of calories, and this time is also a good time to treat some chronic injuries, so there is no kidney problem at all. But if you play ice when you have nothing to do, it will definitely be bad for your health. Your skin has no heat to offset the cold! ! So choose the right time.