Cold exposure has in recent years been popularized by Wim Hof and others. There are many health benefits of cold exposure – it is boosting immune functioning and it can improve general mood. It can however be difficult started. I am currently swimming twice a week in cold water (5-6 degree celcius). If you are a new to cold exposure, I would recommend a gradual adaption to cold temperatures. For example, you might start by exposing only feet or hands. Over time, you may stay longer and expose more of the body. Eventually, it is possible to swim in cold water and from season to season, you can swim longer.