The way to start cold is to stick your head/face directly in to start the shower. That gives you the strongest mammalian dive response. Not sure if that offsets any of the cold shower benefit though.

https://en.m.wikipedia.org/wiki/Diving_reflex

Edit: This is also the time of year to do this, while the tap water is probably warmer and your house is warmer. I wouldn't try to acclimate in winter.

This works great. Just tried it on two occasions. The shower doesn't even feel as cold.

So in short, jump into a pool instead?

Instead of shower? No, you can't find a pool that cold. But I do always recommend jumping in to a pool all at once rather than wading in slowly.

I always like to dump a sewing kit into a pool before I get in, as such a thread pool is instantiated and multiple people can enjoy it concurrently.

s/noodle/needle

Anecdotal, but for some reason, when I tell myself "It's just cold water", my fight or flight response instantly goes away.

"fight or flight" is how you nicknamed your balls? Because when I take a cold shower they do instantly go away!

It's pretty easy to start cold if you've just done a huge amount of cardio, otherwise there's nothing wrong with just turning off the hot water completely during a shower if you want a brief cold period.

For these people that claim taking cold showers, I want water temp. Out of the tap, in summer, my water is 53 degrees (f), upper 40s in winter. I'm not sure I could get through a whole shower sans hypothermia.

Edit: looked it up. 30min-2hr for hypothermia at that range. Typically I take a 15-20 minute shower, so only flirting with hypothermia.

I love a hot, hot shower. Best advancement in technology in the last thousand years

Ha, I have been taking cold showers for a few months, and recording water temp for interest. Currently it’s about 11C/52F. No hypothermia yet :)

My showers are about five minutes, a habit from growing up on tank water during a drought. Water on, jump in, wet your hair, soap, shampoo, wait a minute, rinse, conditioner, wait a minute, rinse, jump out. Cold showers are great motivation to be even faster.

Interestingly, one of the theories behind why cold showers might be good for you is that they induce a heat shock response, same as a very hot shower.

I suspect that if you start taking cold showers, you’ll also star taking shorter showers.

I don’t think there’s anything wrong with starting warm and cooling down. The only thing that matters is that you can go cold enough for a decent amount of time.

For me, there is some value in facing the cold water head-on in the morning ("Wow, this is going to be cold, but here goes!" Great way to start the day. I have to admit though, the cold water is not super cold here this time of year.