Spring is the time when the yang is born but not full, and the yin begins to decrease but not fade. "The monkey face in spring, the climate changes at any time." The climate often changes greatly, but at first it is warm and cold. Due to the warming climate, the human muscle surface begins to drain. In addition, the human body yang is biased towards the body surface. At this time, the cold resistance is relatively poor, especially in early spring, and attention should be paid to preventing colds.