According to a recent survey [調查], less than 1 in 10 Americans sleep in the nude. Nude or not, what’s it matter, as long as we sleep, right? Well, not exactly.  There are benefits to sleeping in the buff and most of those benefits are medical and worth learning about. Nevertheless, Americans prefer sleeping in clothes. This American habit hasn’t stopped curious doctors from studying sleepers, clothed and naked. Let’s hope those other nine Americans switch sides because what the doctors have found about sleeping naked is really amazing.