I’ve spent the past few weeks getting started with trying this cold water business out. More for psychological reasons than anything else.
My home shower goes from hot down to 20C down to 8C, with no in between for that last cold step. Thankfully a week or so in Devon gave me the opportunity to have use of a more reasonably transitioning shower.
Hot shower to wash, then go down to cold for the last few minutes. Since getting home I have managed to stay on the coldest setting here for a couple of minutes - I won’t say those two minutes are easy, but they are bearable.
I actually look forward to doing it every morning. It’s like I am proving I can do uncomfortable things right at the beginning of the day.
Got my first cold (all sinuses and chest) since the pre-Covid times after my holiday, but will see if it has any physical health benefits in the longer term.