Wet is the easiest to penetrate. Damp evil never fights alone, but always colludes with other evil spirits. Moisture becomes cold and wet when it meets cold, just like winter. If the climate is dry, no matter how cold it is, people can still accept it, but if the humidity is high, people will feel very uncomfortable. Winter in the south is more uncomfortable than winter in the north, because the humidity in the south is heavier and the cold and dampness attack people. When moisture is hot, it becomes wet, just like a sauna day in summer. It's hot and humid, which makes people breathless. It's obviously not as good as when the sun is shining and the climate is dry. When moisture meets the wind, it becomes rheumatism, which is easy to drive away the wind, but once it becomes rheumatism, it is often a chronic disease that cannot be cured for a while.