经云∶在天为热，在地为火。暑者，热火之气也。天有此热火之气，人亦有此热火之气。无分四时寒暑，凡
病三阳，而见热火之证，皆可言暑。是寒也，暑也，即阴阳之气也。今人不明人身运气之理，遇炎天酷暑之病，
不曰伤暑，即曰中暑，香薷、石膏、竹叶、芩、连，概投混施，其杀人不知几许矣！夏月之时，世人尽知有暑，用
寒凉之药，人皆曰宜也。服之不愈，则更服之，更服不愈，则频服之，虽至于死，亦无怨言。若遇明者，洞鉴其
源，投以温药，人皆曰不宜也。服之不效，必不再服，其心皇皇曰∶此暑病也，可服热药乎？清凉之药，恣意投
之，厥身已毙，仍咎热药之非，则夏月寒凉杀人，所必不能免者。夫不能免而欲求其免，其在刍言之可听
乎！盖暑者，四时之一气也，暑何害于人哉！如暑而必
伤人也，则长夏之时，尽人当病，何以烈日中奔走劳形者不病，而避暑于高堂大厦者反病耶？须知人病，皆其
自取。吾身五运安和，六气均平，虽日在暑中而不病。若五运有亏，六气不振，阴虚则阳盛而热证生，阳虚则
阴盛而寒证起，寒病、暑病随人身阴阳之气而化生者也。如寒邪伤阳而化病，寒亦为热；暑邪伤阴而化病，暑
亦为寒。苟不以人身气化之寒暑为凭，而以天气之寒暑为定，真杀人不用刃矣！且夏月之时，人身上热下寒，
一如天气虽暑，地下则寒，不观井中水冷之极乎？人身丹田之气，地下之水，亦若是也。凡治病者必顾其本，
惟夏月之病，当温补者，什之七八，宜凉泻者，什之二三。凡人肾气有余，形体不劳，但感风暑。化为热病，
则香薷、白虎，一剂而痊，西瓜、凉水，服之而愈。医见其痊愈也，遇暑邪入脏之证，亦以此药治之，则一剂
而殂者，比比矣。酷暑炎炎，朝病夕死，人谓疫气流行而死者，皆因暑邪入脏病也。其病五六日而死者，亦因
阳气尽泄于外，谷气不入，肾气有亏，真气内脱而死也。如是之病，惟参、 、桂、附可以疗之。疗之而尽人
皆愈也，人或信之；疗之而间有一二不及疗者，人必疑之而非之矣。余尝思子产论政云∶夫火烈，民望而畏
之，故鲜死焉；水弱，民狎而玩之，故多死焉。今人畏热药
而喜寒凉，又何怪乎其多死哉！（戒人当暑月中，须知兼杂虚寒之证，不可恣意凉散。然言之未免太过，读者
当识其大旨，勿以辞害意可耳！）
《黄帝内经》说：在天表现为热，在地表现为火。暑，就是火热之气。天有这种火热之气，人也有这种火热之气。不分四季寒暑，凡是三阳经（太阳、阳明、少阳）的病，出现火热证候的，都可以称为暑病。这寒和暑，其实就是阴阳二气。现在的人不明白人体运气变化的道理，遇到炎热酷暑季节的疾病，不是说是伤暑，就是说是中暑， indiscriminately 使用香薷、石膏、竹叶、黄芩、黄连等药物，胡乱投药，不知害死了多少人！夏季的时候，世人都知道有暑邪，使用寒凉的药物，人们都说适宜。服用后不痊愈，就继续服用；再服用还不愈，就频繁服用，即使因此死亡，也没有怨言。如果遇到明医，洞察病因本源，投以温性药物，人们都说不适宜。服用后没有效果，一定不再服用，心里惶恐地说：“这是暑病，可以服用热药吗？”清凉的药物，肆意投用，身体已经死亡，仍然责怪热药不对，那么夏季因寒凉药物致死的情况，是必然不能避免的。既然不能避免而想要寻求避免的方法，难道那些浅陋的言论值得听取吗？
暑，只是四时之一的气，暑本身对人有什么危害呢！如果暑必然伤人，那么在长夏时节，所有人都应该生病，为什么在烈日下奔走劳作的人不生病，而在高楼大厦中避暑的人反而生病呢？必须知道人的疾病，都是自取的。我身五运安和，六气均平，虽然每天处在暑热之中也不生病。如果五运有亏损，六气不振作，阴虚则阳盛而产生热证，阳虚则阴盛而产生寒证，寒病、暑病都是随着人身阴阳之气而化生出来的。比如寒邪损伤阳气而化生病变，寒也可以转化为热；暑邪损伤阴液而化生病变，暑也可以转化为寒。如果不以人身气化产生的寒暑为依据，而以天气的寒暑为定论，真是不用刀枪就能杀人啊！况且夏季的时候，人身上热下寒，就像天气虽然炎热，地下却是寒冷的，没看过井水极冷吗？人体的丹田之气，就像地下的水一样，也是如此。大凡治病必须顾护根本，只有夏季的疾病，应当温补的占十分之七八，适宜凉泻的占十分之二三。凡是肾气充足，形体不劳累，只是感受风暑，转化为热病的，那么香薷饮、白虎汤，一剂就能痊愈，西瓜、凉水，服用后也能好。医生看到他们痊愈了，遇到暑邪入脏的证候，也用这些药治疗，那么一剂就死亡的，比比皆是。酷暑炎炎，早上得病晚上就死，人们认为是疫气流行致死的，都是因为暑邪入脏的病。那种病五六天死亡的，也是因为阳气完全泄于外，谷气不能进入，肾气亏损，真气在内脱失而死。这样的病，只有人参、干姜、桂枝、附子可以治疗。治疗而所有人都痊愈了，人们或许会相信；治疗而偶尔有一两个没能治好的，人们一定会怀疑并非议它。我曾经思考子产论政时说：火猛烈，百姓望而生畏，所以很少死于其中；水柔弱，百姓亲近而玩弄它，所以多死于其中。现在人们畏惧热药而喜欢寒凉，又怪得了他们死得多吗！（告诫人们在暑月中，须知兼杂虚寒的证候，不可肆意使用凉散药物。然而话说未免太过，读者应当识得其主旨，不要因为辞藻而损害原意即可！）
The *Classic of Medicine* (Huangdi Neijing) states: "In the heaven, it manifests as heat; in the earth, it manifests as fire." Shu (Summerheat) is the Qi of fire and heat. Just as Heaven possesses this Qi of fire and heat, so does humanity. Regardless of the seasons' cold or heat, any disease involving the Three Yang channels (Taiyang, Yangming, Shaoyang) that presents with symptoms of fire and heat can be termed Shu disease. Thus, Cold and Shu are simply the Qi of Yin and Yang. Today's people do not understand the principles of physiological luck transformation; when encountering diseases during scorching summer heat, they either diagnose it as "Shangshu" (injury by summerheat) or "Zhongshu" (struck by summerheat), indiscriminately administering herbs such as Xiangru (Moslae Herba), Shigao (Gypsum Fibrosum), Zhuye (Bambusae Folium), Huangqin (Scutellariae Radix), and Lianzi (Nelumbinis Semen). This reckless prescribing has caused countless deaths! In summer, everyone knows of Summerheat, and using cold-cooling medicines is considered appropriate. If the patient does not recover after taking them, more is given; if still no recovery, frequent doses are administered. Even if death ensues, there is no complaint. However, if a skilled physician identifies the root cause and prescribes warm medicines, people will say it is inappropriate. If ineffective, they stop taking it, thinking anxiously: "This is a Shu disease; can one take hot medicines?" People recklessly administer cooling medicines until death occurs, yet still blame the hot medicines for being wrong. Thus, deaths caused by cold-cooling medicines in summer are inevitable. To seek avoidance of this inevitability, should one listen to shallow opinions?
Shu is merely one of the Four Seasons' Qi; how can Shu itself harm humans? If Shu inevitably harmed people, then during Changxia (Late Summer), everyone would fall ill. Why do those laboring under the blazing sun remain healthy, while those avoiding heat in high halls and large buildings fall ill? One must realize that human illness is self-inflicted. If one's Five Movements (Wuyun) are harmonious and Six Qi (Liuqi) are balanced, one will not fall ill even amidst constant summerheat. Conversely, if Wuyun is deficient and Liuqi fails to flourish, Yin deficiency leads to Yang excess and heat syndromes arise; Yang deficiency leads to Yin excess and cold syndromes emerge. Cold and Shu diseases are generated according to the body's Yin-Yang Qi transformation. For instance, if Cold pathogen damages Yang and transforms into pathology, Cold can become Heat; if Shu pathogen damages Yin and transforms into pathology, Shu can become Cold. If one does not rely on the body's internal Qi transformation regarding cold/heat, but instead rigidly adheres to external weather conditions, it is truly killing without weapons! Moreover, in summer, the human body often presents with upper heat and lower cold, similar to how the air is hot but the ground is cool, as seen in extremely cold well water. The Qi of the Dantian in the human body is analogous to underground water. In treating diseases, one must attend to the root. In summer illnesses, approximately 70-80% require warm tonification, while only 20-30% are suitable for cooling purgation. For individuals with abundant Kidney Qi and unexhausted physical strength, who merely contract Wind-Shu transforming into heat disease, formulas like Xiangru Tang (Mosla Decoction) or Baihu Tang (White Tiger Decoction) can cure in one dose; watermelon and cold water may also suffice. Physicians, seeing these recoveries, apply these same remedies to cases of Shu pathogen entering the Zang organs, resulting in frequent deaths after a single dose. During intense summer heat, some die from morning to evening; people attribute this to epidemic Qi, but it is actually due to Shu pathogen entering the Zang organs. Those dying after five or six days do so because Yang Qi has been entirely exhausted externally, Grain Qi cannot enter, Kidney Qi is depleted, and True Qi collapses internally. Such conditions can only be treated with Renshen (Ginseng Radix et Rhizoma), Ganjiang (Zingiberis Rhizoma), Guizhi (Cinnamomi Ramulus), and Fuzi (Aconiti Lateralis Radix Praeparata). If treatment succeeds and all recover, people may believe it; if occasional failures occur, people will doubt and criticize it. I once reflected on Zichan's discussion on governance: "Fire is fierce; people fear it, so few die in it. Water is weak; people play with it, so many die in it." Today, people fear hot medicines and prefer cold ones; is it surprising that they die frequently? (This warns that during summer, one must recognize mixed deficiency-cold syndromes and avoid reckless use of cooling dispersants. Although the statement may seem extreme, readers should grasp the main intent and not let literal wording obscure the deeper meaning.)