LIBERATING

To Noah Grosshandler, sleeping nude feels freeing. For three years now, the 24-year-old technology project manager in New York has shed the boxers and T-shirts he once wore to bed to go au naturel. He just finds slumbering in the buff more comfortable than wearing bunchy underwear. And while he isn’t convinced that nudity improved the quality of his shut-eye, he fears switching back would erode it. “If I went back, I think I would probably sleep worse.”

Every night, men and women around the U.S. make the same choice...