There are few scientific studies on the practice, but Tracy Zaslow, a 48-year-old sports medicine doctor at Cedars Sinai in Los Angeles, said there is data that suggests cold exposure can at least help with muscle soreness. The science on whether regular cold plunges can help with anxiety and weight loss is less clear.
Ms. Schramm and Dr. Zaslow cautioned that cold-plunge newbies should speak to their primary care doctors before dipping into an ice bath for the first time. The biggest risk of cold exposure is hypothermia, Dr. Zaslow said, and there are also rare cases in which cold exposure can trigger cardiac arrest or arrhythmias, especially in people with underlying health conditions.