Extreme heat produces cold, and extreme cold produces heat. How do you say this?

Literally, it means that it will become cold when it is hot to the extreme, and it will become hot when it is cold to the extreme.

The most popular term refers to the change of seasons, that is to say, the weather will gradually turn cold after reaching the hottest in summer, and then it will start to get hot after the coldest in winter.

According to China's traditional theory of Yin and Yang, Yin and Yang will transform into each other under certain conditions, which are "extreme". For example, "Su Wen Yin and Yang should be like a big theory" said: "Heavy yin must be yang, and double ninth must be yin."

The same is true in pathology. In the view of Chinese medicine, when the cold syndrome develops to the extreme, there will be deficiency heat; On the other hand, if the symptoms of heat develop to the extreme, there will also be deficiency cold. "Lingshu Disease Diagnosis Ruler" said: "Four seasons change, cold and summer are prevalent, and yin must be yang, so yin dominates cold and yang dominates heat, so cold is hot and heat is cold."