When I turn on the hot water in my apartment, it takes a split second for the hot water heater to engage. After the heater turns on, I'll see a steady stream of reddish colored water for a few seconds before the water becomes clear. The reddish water comes from the rust that has accumulated in the hot water pipes, and that rust in turn is caused by the high mineral content of the water in Shanghai.
Just another reason why most people don't drink the Shanghai water out of the tap (not even after boiling it, because you can't boil away minerals and metals). No, what most people have are 饮水机 (yinshuiji), or water coolers. Given the popularity of tea in China, almost all water coolers have a heater built in - the one in my apartment is no different - so that you can get both hot and room temperature water.
But all that above info is really to set the stage for what I think is a really nasty Chinese habit. I'm talking, of course, about the insidious habit that Chinese people have of drinking lukewarm water. Talk about disgusting! I mean, I enjoy the rare cup of tea here and there, but for the most part, I like my water cold or at the very least, room temperature. Imagine my surprise then, when about half the office support staff (4 ladies) chided me for drinking room temperature water while my stomach was hurting. They explained that the warm water would be less "shocking" to my sensitive stomach and thus better than cold or room temperature water. It made sense to me then so I followed their advice and put some hot water into my cup with my cold water.
Talk about a strange sensation. It's not quite the soothing sensation one experiences when drinking a hot beverage nor is it anywhere close the refreshing feeling you get when you drink cold water. It's just... weird.
So after my stomach felt better, I started drinking room temperature water again, thinking I didn't need warm water anymore! Yeah, no dice. While pouring myself a cold glass of water, a co-worker reminds me that drinking cold water will only bring back or cause more stomach pains. Later on, during lunch, I'm enjoying a nice glass of water with my food when another co-worker tells me that drinking fluids of any kind, but especially water, is really bad for digestion. She contends that the water dilutes the stomach acids and thus messes up the digestion process.
I mean, I can sort of understand the reasoning behind my co-workers' contentions, but really, I've been drinking fluids with my meals for all of my life and I've been drinking cold/room temperature water forever! I think I vaguely recall that back when my grandmother was still alive she would also drink warm water, but I just attributed that to her advancing age and loss of teeth (i.e. gums would be too sensitive to cold water), but who knows... maybe she drank it for health reasons.
But the WORST part of all this... is the water cooler at my house. Apparently the heater is super-extra-crazy strong in my water cooler so the hot water comes out scalding... and the cold water comes out... you guessed it! WARM!
So now when I drink water at home, I drink warm water... hating each sip I take. Hating myself for not unplugging the damn water cooler just in case I need hot water for something.