Spring and summer are yang orders. In spring, yang is born, and in summer, yang is strong. In spring, yang begins to grow, and wind and cold evils are still common. Therefore, you should pay attention to keeping warm from the cold in spring. Folk proverbs say that it is not advisable to reduce clothes too early in spring. This is also the reason to nourish the yang of the human body. In summer, the Yang is extremely strong, and the summer heat evil is strong. Severe heat consumes Qi, and Qi is Yang, so severe heat also damages the Yang of the human body. People like to enjoy the coolness on summer nights, and are susceptible to cold and dampness, which can damage yang. Summer is hot, and people like cold drinks. Excessive eating can easily damage the yang. Therefore, in summer, it is necessary to stay in a cool place to avoid the heat, and avoid eating too much cold drinks to prevent yang damage. To enjoy the coolness on a summer night, avoid moisture and dew, and cover it appropriately. , to avoid cold and dampness.

Autumn and winter are also yin orders. In autumn, yin harvests and in winter, yin hides. In autumn and winter, dryness is a common problem and it is easy to damage yin. Therefore, it is advisable to take yin-nourishing products or apply moisturizing and skin care products to prevent dryness. Keeping the air in the room moist will also help to avoid dryness. It gets colder in autumn and becomes colder in winter. People like to eat spicy food and drink alcohol to keep out the cold. Spicy food can easily cause internal heat, wine can easily cause dampness and heat, and eating too much can damage yin. Therefore, in autumn and winter, we should not only avoid dryness evil, but also avoid overeating spicy food and drinking too much alcohol to prevent yin damage.

People think that the warm evil in spring and the hot evil in summer can easily damage yin, so you should nourish yin in spring and summer; the cool evil in autumn and the cold evil in winter can easily damage yang, so you should nourish yang in autumn and winter. Why does the "Nei Jing" only emphasize "nourishing yang in spring and summer, nourishing yin in autumn and winter"? It is well known that warm spring and summer heat can easily damage yin, while cool autumn and cold winter can easily damage yang. And in spring and summer, people know how to nourish yin but don't know how to nourish yang; in autumn and winter, people know how to nourish yang but don't know how to nourish yin. Therefore, in spring and summer, there are people who seek to nourish yin but harm yang; in autumn and winter, there are people who seek to nourish yang but harm yin.

The "Nei Jing" says that "the sage nourishes yang in spring and summer, nourishes yin in autumn and winter" because many people in the world are negligent, but sages who are good at maintaining health can understand it, so as to obey the changes of yin and yang in the four seasons. Its roots".