You watched “a video”? Dude I take cold showers in the summer and the winter all the time because it helps with muscle recovery and i get better sleep. As long as your not letting your body go hypothermic your totally fine.

And if you are one of those people that thinks you’re hardcore because you let your body go hypothermic you are not. Your an idiot. You should always make sure that you have someone who is monitoring you if your going to be in an extremely cold environment or cold water for an extended period of time. It is not safe to do this on a regular basis but if you are doing it for military training, police training, or in some kind of competitive environment, obviously make sure you have someone monitoring you.