We recently had lunch with Chinese friends at a hot pot restaurant and had hot peanut milk. This made me remember just how rare it is to get cold water (lěng shuǐ, 冷水) or other cold drinks when you you eat out at restaurants.
This is because Chinese people believe that cold drinks are bad for your health. Specifically, drinking cold drinks is bad for your stomach. However, not drinking cold water in China is actually a good thing because you are much less likely to get sick from drinking hot tea than you are from drinking the tap water (which no one drinks unless its boiled). But it can also make you want to bring your own ice water in the summer.
Ironically, eating ice cream is considered very healthy in the summer though, so I am not sure why ice water is still unhealthy. Ice cream and anything else cold is of course considered practically lethal in the winter, and almost disappears from some local stores here during colder months.