I recently moved to Singapore and assumed cold showers were pretty much the norm here. Can confirm it's not comparable to having a cold shower elsewhere though, in terms of willpower :)

Perhaps a river or lake can provide you with colder temperatures? I've got a similar issue, I practice outdoor swimming the year round and the temperature doesn't get below 4 degrees. I've got to move countries to swim in colder water

> Perhaps a river or lake can provide you with colder temperatures?

Nah, down there in the equatorial tropics, the only things that get much below 20°C are those in fridges or freezers. The aircons don't go below 16°C.

Not really, unfortunately:

http://www.seatemperature.org/asia/singapore/singapore.htm

I'm not sure a 20 degree shower really counts as a cold shower. That is a comfortable swimming temperature on most summer days and people can easily spend 20-30 minutes in water just to cool off even if they are unaccustomed to taking cold showers at home.

I've only been to such hot countries on vacation, and I think if asked, most people would confirm that they mostly don't use the hot water, except perhaps to sanitize hands with soap.