I can't find much convincing official research (just blogs) to support that cold showers are beneficial to skincare, but I've been taking them nonetheless, and honestly, my pores have looked better :)
This applies to pretty much EVERYTHING that is not done via high quality double-blind studies published in reputable, peer-reviewed journals.
Point being: Repeating single actions of successful people statistically does not make you successful.
As an example, there was a study that eating a handful of almonds every day is correlated with a bunch of positive health outcomes. Then a follow-up paper determined that this is simply because nuts are a relatively expensive snack, so they're eaten regularly mostly by wealthier people. It's well established that being poor is bad for your health, and conversely being rich tends to allow healthy lifestyles in general.
The kind of people that take cold showers are the "health-nut" types that prioritise healthy living over comfort. They're a rare, self-selecting subset of the general population.
It's extremely difficult to do good science based on statistics of self-selecting groups, or groups highly correlated with wealth.
I would probably be characterized as one of the "health-nuts," so between the cold showers, moisturizing twice a day, trying to perfect my indoor air pollution, and literally eating raw spinach and a bowl of fruit for lunch... Who knows what contributes to what?
I probably have health anxiety. I wouldn't characterize it as extreme, but it does force me to do anything I hear is healthy for me.
Seems really warm!
Nitpick: it is difficult to take a shower with water in solid form (ice).
> Nitpick: it is difficult to take a shower with water in solid form (ice).
Nitpick: having a temperature below zero does not necessarily mean that it is in a solid form; for example, it could be at a high pressure or not have a nucleus to freeze around (supercooling).
Bonus points if you can scale it up to a mannequin.
The first, pounding it inside the sealed bottle, is creating some sort of disturbance to crystalize around (an "unsuspecting nucleus"), and the second is pouring it semi-shower-like.
I do think it would be interesting to see it, though.
But I guess it depends on your knobs shower knobs.
I agree cold, hot, warm are all relative. Somewhat related I've seen people from hot countries worry about "cold weather". To them ~20C is cold compared to 35C hot day and was blamed to be the cause of colds and flu. Often perpetuated in movies and TV too a tired old trope. So yes to someone in a hot country a "cold" shower may be considered warm to someone from a cold climate.
My record for cold shower temperature was 39.9F (4.4C), here in New York City. Five minutes at that temperature bordered on pain. My fingertips turned purple.
The warmest cold shower I took was in Brazil. Sadly, I didn't get to enjoy it because I was sunburned.