Dear Doctors: It's a tradition in my husband's family to start the new year with a dip in the ocean. We live in Maryland, so that means it's freezing cold. I see on social media that doing a cold plunge is now a craze. Is it true what they're saying, that it's good for you?
Dear Reader: Enthusiasts on TikTok, where cold plunge videos are amassing millions of views, are advocating a practice that da…