Most Times I can't bring myself to get into a cold shower. If I start warm I can cool down from there. Is there a way to start cold and go even colder?
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.
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
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.