I’ve done it only once — on a dare.
I was on the John Muir Trail in California.
Camping in a remote spot — far from any other people — I took off for about 45 minutes wearing only my hiking shoes.

Nude hiking, also known as naked walking or freehiking, is a sub-category of the modern form of social nudity. More popular in Europe than anywhere else.
Personally, I didn’t particularly enjoy hiking naked. And have not yet been tempted to try it again.
But if you want to know more, there’s an article on Planet Nude that explains the benefits:

