I used to have cold showers till 21. Then I was told that warm shower ( cozy) is better for health. I started warm shower and didn't find any difference between the two.

Recently I watched videos by Andrew Hubermann ( I highly recommend you too watch as you have done in depth analysis of cold showers) which talks about the link to dopamine and cold showers

You might want to watch his long educative videos or in YouTube shorts
Search for
Andrew Hubermann cold showers

You will see sevaral videos.

I am tempted to start cold showers but I guess I can shift gradually only