There are studies of the benefits and risks: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7730683/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7730683/ From t

There are studies of the benefits and risks: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7730683/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7730683/ From the cardiovascular section: "Several studies have described a positive effect on the cardiovascular system and cardiovascular risk factors. Cold water swimming appears to have a positive impact on cardiovascular risk factors such as lipid profile [23,24,56] or blood pressure [53]." (This study focuses on the athlete level long duration cold water swimming, but also considers short term exercise, something to keep in mind if you just skip to the conclusions) And it's a recreation activity with a long history in some parts: https://www.theguardian.com/global/2018/dec/23/the-big-chill-the-health-benefits-of-swimming-in-ice-water https://www.theguardian.com/global/2018/dec/23/the-big-chill... It's mostly good for you, but like many kinds of exercise and physical exertion you can also have adverse effects if you have poor health and/or get foolhardy before learning to do it.