The theory of winter sickness and summer treatment in three-volt days originates from the meridian theory, the doctrine of yin and yang and the five elements. 1. Meridian theory. Yellow Emperor’s Internal Canon has a cloud: “summer qi in the Sun Luo, in the skin.” The climate is hot on the day of three volts, the human body qi and blood operation is more active than other periods, the skin pores are easy to open, the nature of the warm medicines on the skin, easier to be absorbed, thus encouraging the body’s yang qi, it is easier to get rid of the cold. 2. Yin and Yang theory. Yellow Emperor’s Classic of Internal Medicine has a cloud: “Sage spring and summer Yang, fall and winter Yin.” Voltaic is the more vigorous time of the year, the human body within the cold easy to solve, at this time to raise the yang can rely on nature’s yang as well as the power of the drug, so that their own yang can be cultivated and replenished. For the cold inside the disease, the effect is better, especially for cold, cold and dampness type of disease. 3. Five elements theory. Three-volt day belongs to the long summer, long summer season corresponds to the five elements is earth. In winter, the corresponding five elements are water. In the relationship between the five elements, earth and water, that is, “long summer wins winter”, so winter diseases can be treated in summer. San Fu paste has clear indications and contraindications, should be operated by a physician, should not be used without authorization, in order to avoid poor efficacy or adverse reactions.