1. Since the Shang Dynasty, the aristocratic royal family has the habit of storing ice cubes in winter for use in summer. There are related records in The Book of Songs.

I remember that someone once designed a water temple. Water is pumped to a high place by the waterwheel and flows down the roof eaves, forming an effect similar to that of water curtain cave. Take away heat through running water, there is no heat inside.

The emperor will drink a bowl of soup to cool off the heat and soothe the nerves before going to bed. This method is also very common.