Came across this story as I'm headed there in a few hours. I have to side with Hugh on this one as he got it half right. If you ever go to Japan, they hand you a small towel and it serves a dual purpose. You are technically suppose to use it to cover yourself when moving around and about but once in the water, it shall go on your head if you are a hot springs pro. The reason for the latter is debatable ... to help your body adjust to the hot springs and cool the head. I think you are better off with a cold beer.

http://www.jaunted.com/story/2013/7/15/151111/137/travel/Even+Hugh+Jackman+is+Awkward+When+It+Comes+to+Spa+Etiquette+in+Japan