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Summerheat disorders manifest as restlessness, a deficient pulse, red urine, fever, thirst, and sighing. For mild cases, Tianshui San (also known as Liuyi San) should be used to eliminate pathogens via urination; for severe cases, Xiangru Yin should be taken to induce sweating and remove pathogens. Baihu Tang demonstrates significant efficacy in cases of profuse sweating and unrelenting thirst. Lizhong Tang can be referenced from past precedents to treat counterflow syndromes (In summer, latent yin exists within the body, often leading to Huoluan [Cholera-like disease] and diarrhea syndromes. If thirsty, Wuling San is indicated; if not thirsty, Lizhong Tang is indicated. This is the method of the Sages. I witnessed personally the physician Zheng Peizai suffering from vomiting and diarrhea. He took Huoxiang Zhengqi San in the morning and died by evening due to profuse sweating. This serves as a warning from the past. If Lizhong Tang had been urgently administered, he could have been saved.) The text mentions that cold knees indicate the presence of dampness, a view found in the works of Li Dongyuan (Cangzhu Baihu Tang is recorded in *Dongyuan Shishu*).

Those who run and labor under the midday sun do not fall ill, whereas those who avoid summerheat in high halls and large mansions do. One must realize that human illnesses are often self-inflicted. If one's Five Movements are harmonious and Six Qi are balanced, one will not fall ill even amidst summerheat. If one's Five Movements are deficient and Six Qi fail to flourish, yin deficiency leads to yang excess and heat disorders arise, while yang deficiency leads to yin excess and cold disorders emerge. Cold and summerheat diseases are generated according to the transformation of the body's yin and yang qi. For instance, cold pathogenic factors damaging yang qi may transform into heat; conversely, summerheat pathogenic factors damaging yin qi may transform into cold. If treatment is not based on the cold and heat generated by the body's physiological transformation but rather determined solely by the weather's cold and heat, it would truly kill without using blades. Furthermore, during summer, the human body is hot above and cold below, just as the earth is cold beneath despite the hot weather. Have you not observed how extremely cold well water is? The qi of the Dantian in the human body is analogous to the water underground. In treating any disease, one must attend to the root. Specifically for summer diseases, seven or eight out of ten cases require warming and tonification, while only two or three out of ten are suitable for cooling and purging. Individuals with abundant Kidney qi and unexhausted physical strength who contract wind-summerheat transforming into heat disorders can recover with a single dose of Huoxiang Zhengqi San or Baihu Tang, or by consuming watermelon and cold water. Physicians, seeing such recoveries, may mistakenly apply these same remedies to cases where summerheat pathogens enter the Zang organs, resulting in death after a single dose being commonplace. During intense summer heat, patients may die from morning illness to evening death. People attribute this to epidemic qi, but it is actually caused by summerheat pathogens entering the Zang organs. Death occurring after five or six days results from the complete exhaustion of yang qi through external leakage, failure of grain qi to enter, depletion of Kidney qi, and internal collapse of true qi. Such diseases can only be treated with Renshen (Ginseng), Rougui (Cinnamon Bark), and Fuzi (Aconite Root); upon treatment, all patients recover. If people believe this, and occasionally one or two fail to recover despite treatment, others will inevitably doubt and criticize it. I once reflected on Zichan's discussion on governance: "Fire is fierce; people fear it, so few die from it. Water is weak; people play with it, so many die from it." Today, people detest warm medicines and prefer cold ones; no wonder their mortality rate is high. (This warns that amidst summer heat, one must recognize concurrent deficiency-cold syndromes and avoid indiscriminate use of cooling and dispersing agents. However, the statement may be somewhat exaggerated; readers should grasp the main intent and not let the wording obscure the meaning.)

Dampness disorders present with a slow pulse, heavy head, heavy and painful limbs, and loose stools. Erchen Tang combined with Cangzhu (Atractylodis Rhizoma) and Baizhu (Atractylodis Macrocephalae Rhizoma) is appropriate, with further modifications based on symptoms.
(Interpretation of Classics) *Taiyin Yangming Lun* states: "When injured by dampness, the lower part of the body receives it first." *Shiyi* annotates: "Yin-dampness pathogenic factor. The lower part of the human body belongs to the yin aspect. Yin follows yin, hence the lower body is affected first, subsequently spreading upward, causing pain throughout the body, which is its characteristic sign." *Jingui Yaolue* utilizes Mahuang Jia Baizhu Tang, with the most detailed discussion; it should be studied thoroughly.