A lot of westerners are mocking that Chinese drink hot/warm water in all the season. I did a research by checking the doctor's comments online. The doctory saies westerners ate a lot of high calories food in their daily life so their body is quite warm, drinking cold water actually helps keep a balance of their healthy. While the Chinese's food diet is very diffrent and drinking hot and warm water actually helps them to keep a balance of healthy.
It is like why Sichuan people won't get sick after eatting so much spicy food but ZheJiang people will get sick,because of the whether and their body system has used to it.