Dr. Elizabeth Yuko is a bioethicist and adjunct professor of ethics at Fordham University. She has written for The New York Times, The Washington Post, The Atlantic, Rolling Stone, CNN & Playboy.

Even if you can't see 'em. We wash our bedding, keep under the bed spotless, and dust the headboard weekly, but when's the last time you actually cleaned your mattress? (And no, flipping it doesn't ...