Coldness in the lower legs and shins, abdominal distension due to deficiency, green-colored stool, vomiting of milk and food, blueish eyes, cyanotic and pale complexion, deep and faint pulse—these are all manifestations of Cold Syndromes (Han Zheng), for which cold-natured medicines should not be used.

Heat in the lower legs and shins, redness of both cheeks, constipation, reddish urine, unquenchable thirst, upward rushing of Qi with rapid breathing, tight and rapid pulse—these are all indications of Heat Patterns (Re Hou), for which hot-natured medicines should not be used.

The principle of medication application requires avoiding rigid adherence to ancient prescriptions. One must adjust the ingredients according to the severity of the syndrome. The subtle distinctions between cold and heat must strictly conform to medical logic. It is absolutely essential to avoid reckless administration or erroneous prescription of pills and powders, as such actions can cause fatal harm in an instant, violating the laws of nature. How can a physician not exercise caution? Substances such as Realgar (Xionghuang), Natrii Sulfas (Yanxiao), Quartz (Shiyin), Borax (Pengsha), and Cinnabar (Dansha) must not be decocted over fire. Rhizoma Aconiti Lateralis Preparatum (Chuanwu), Radix Aconiti Lateralis Preparata (Fuzi), Curcumae Longae Rhizoma (Yujin), Arisaematis Rhizoma (Nanxing), and Pinelliae Rhizoma (Banxia) must not be used raw. They must be processed meticulously according to standard methods; only then will the medicines invariably achieve efficacy.

For diseases located above the chest and diaphragm, food should be taken before administering medicine. For diseases located below the heart and abdomen, medicine should be administered before taking food. For diseases located in the four limbs and blood vessels, it is appropriate to take the medicine on an empty stomach in the morning. For diseases located in the bone marrow, it is appropriate to take the medicine when full at night. For diseases located in the exterior (Biao), there are no specific time restrictions.

Ancient formulas mention "Jinyin Bohe Tang" (Honeysuckle and Mint Decoction). This led later physicians to erroneously add silver earrings to mint for decoction, which is highly illogical. Earrings are items commonly worn by women, often soaked in dirt and grease. Using them for decoction contaminates the medicinal flavor, which is highly inappropriate. In the past, He Cheng discussed "Jinyin Bohe," referring specifically to "Jinqian Bohe" (Coin Mint). Currently, the mint leaves grown in gardens that are small like coins are verified to be named Jinqian Bohe. This principle is clear; it does not imply adding gold and silver for decoction. The error likely arose because the character for "coin" (Qian) resembles "silver" (Yin), leading to transmission of mistakes. This is similar to textual corruptions where characters look alike but differ in meaning (e.g., fish vs. rooster).

Ginger has a pungent and slightly warm flavor and is non-toxic. Raw ginger disperses cold pathogens, while prepared ginger (Paojiang) stabilizes the middle and harmonizes the stomach. Dates have a sweet and neutral flavor and are non-toxic. They nourish the spleen and stomach and harmonize various medicines. They should be decocted after removing the pits. If the pits are not removed, they may cause irritability and oppression.

The Way of Medicine is indeed difficult. Treating children is particularly challenging. Sun Simiao stated: "One who can cure ten men may not be able to cure one woman." Why? Men have robust Ying and Wei Qi (Defensive and Nutritive Qi). Women's blood and vessels are subject to fluctuations from menstruation and childbirth, making their treatment more difficult. The *Qianjin Fang* states: "Women's diseases are ten times harder to treat than men's." It also states: "One who can cure ten women may not be able to cure one child." Why? Women can describe their symptoms, and their blood and Qi are relatively intact. Children cannot speak, their spirit and essence are not fully developed, and pulse diagnosis is difficult to rely upon. Hence, it is said to be difficult.