Cold plunge resorts have moved from a niche Scandinavian ritual to one of the most sought-after categories in luxury wellness travel. Travelers are booking trips built specifically around freezing-water immersion, sauna circuits and recovery-focused spa programming, and resorts from Iceland to Arizona are designing entire experiences around the practice. The shift has been fast. Cold plunging - submerging the body in water below 60 degrees Fahrenheit for short periods, often paired with saunas and hot tubs - went mainstream during the pandemic and has kept climbing since.