Cold-plunge breakfast is a TikTok routine combining cold plunges with breakfast, often as part of wellness-bro content. Not concerning, generally safe; cold plunges can carry risks for some. If your kid uses it constantly, ask them where they first heard it, not to police their speech but to understand which online community they are in. Most slang of this kind moves through TikTok and group chats, so seeing it in your child's vocabulary just means they are plugged into normal teen internet culture.