风暑湿燥寒，乃天地之气行于四时者也。惟夏令属火，日光最烈。《内经》云∶岁火太过，炎暑流行。明指烈日之
火而言。然春秋冬三时之暖燠，无非离照之光热，因皆不可以暑称。故轩岐于五气之下，赘一火字。且其言暑，明曰∶
在天为热，在地为火，其性为暑。是暑 热与火二者而已，经旨已深切着明矣。而人之火病独多者，以风寒暑湿，悉能
化火，五志过动，无不生火，则又天气与人性交合化火之大源也。
，即暑也。变暑言 者，以暑病属诸伏寒，至夏至后发病之名，故曰中 。使不相混，此仲师法也。
伤寒非汗不解，最喜发汗；伤风亦非汗不解，最忌发汗，只宜解肌。此麻、桂之异其治，即异其法也。温病亦喜汗
解，最忌发汗，只许辛凉解肌，辛温又不可用，妙在导邪外出。俾营卫气血调和，自然得汗，不必强责其汗也。若暑温
湿温，则又不然。暑非汗不解，可用香薷发之。发汗之后，大汗不止，仍归白虎法，固不比伤寒伤风汗漏不止，而必欲
桂附护阳实表。亦不可屡虚其表，致令厥脱也。观古人暑门，有生脉散（人参、麦冬、五味子）法，其义自见。
外感不外六淫，民病当分四气。治伤寒家，徒守发表攻里之成方，不计辛热苦寒之贻害，遂使温热之旨，蒙昧不明。
仆不敏，博览群书，恍然于温热病之不可不讲也。《内经》云∶冬不藏精，春必病温。盖谓冬时严寒，阳气内敛，人能
顺天时而固密，则肾气内充，命门为三焦之别使，亦得固腠理而护皮毛，虽当春令升泄之时，而我身之真气，内外弥沦，
不随升令之泄而告匮，纵有客邪，安能内侵？是《内经》所以明致病之原也。然但云冬不藏精，而不及他时者，以冬为
水旺之时，属北方寒水之化，于时为冬，于人为肾，井水温而坚冰至，阴外阳内，有习坎之义，故立言归重于冬，非谓
冬宜藏，而他时可不藏精也。即春必病温之语，亦是就近指点。总见里虚者表不固，一切时邪，皆易感受。学人可因此
而悟及四时六气之为病矣。《难经》云∶伤寒有五∶有伤寒，有中风，有风温，有热病，有湿温。夫统此风寒湿热之邪，
而皆名之曰伤寒者，亦早鉴于寒脏受伤，外邪得入，故探其本，而皆谓之伤寒也。大致西北风高土燥，风寒之为病居多；
东南地界水湿，湿热之伤人独甚。从来风寒伤形，伤形者定从表入；湿热伤气，伤气者不尽从表入。风邪外束，则曰风
温；湿邪内侵，则曰湿温；纵有微寒之兼袭，不同栗冽之严威，是以发表宜辛凉，不宜辛热；清里宜泄热，不宜逐热。
使概投以发表不远热，攻里不远寒诸法，则死亡接踵矣。
风、暑、湿、燥、寒，是天地之气在四季中运行的表现。只有夏季属于火，日光最为猛烈。《内经》说：“岁火太过，炎暑流行。”明确指的是烈日的火气而言。然而春、秋、冬三季的温暖，无非也是太阳的光芒热量，因此都不能称为“暑”。所以岐伯（轩岐）在五气之下，多出了一个“火”字。而且他说暑，明确指出：“在天为热，在地为火，其性为暑。”这说明暑就是热与火二者而已，经旨已经深切明显了。而人的火病之所以独多，是因为风寒暑湿，都能化火，五志过动，无不生火，这又是天气与人性交合化火的根本源头。
暍（yē），即暑也。将暑病称为暍，是因为暑病归属于伏寒，到夏至后发病的名称，所以叫作中暍。为了使两者不混淆，这是张仲景的治法。
伤寒非发汗不能解除，最喜欢发汗；伤风也非发汗不能解除，但最忌讳发汗，只适宜解肌。这就是麻黄汤、桂枝汤治疗方法的差异，也就是治法的不同。温病也喜欢通过汗解，但最忌讳强行发汗，只允许用辛凉药物解肌，辛温药物不可使用，妙处在于引导邪气外出。使得营卫气血调和，自然出汗，不必强求发汗。如果是暑温、湿温，则又不一样。暑病非发汗不能解除，可以用香薷发散。发汗之后，如果大汗不止，仍然回归白虎汤法，固然不像伤寒、伤风汗漏不止那样，必须用桂枝、附子护阳实表。也不可以屡次虚损体表，导致四肢厥冷和脱证。看古人在暑门中，有生脉散（人参、麦冬、五味子）的法度，其中的义理自然显现。
外感病不外乎六淫，百姓的疾病应当分为四气。治疗伤寒的医生，死守发表攻里的成方，不计较辛热苦寒带来的危害，致使温热的宗旨，蒙昧不明。我不才，博览群书，恍然明白温热病是不可不讲求的。《内经》说：“冬不藏精，春必病温。”大概是指冬季严寒，阳气内敛，人若能顺应天时固密，则肾气内充，命门作为三焦的别使，也能固护腠理而保护皮毛，即使正当春季升泄之时，而我身的真气，内外弥漫，不随着升令的泄而告罄，纵然有客邪，怎么能内侵？这是《内经》阐明致病原因的地方。然而只说冬不藏精，而不提其他季节，是因为冬季是水旺之时，属于北方寒水之化，于时为冬，于人为肾，井水温而坚冰至，阴在外阳在内，有习坎卦的含义，所以立言归重于冬季，并非说冬季宜藏精，而其他季节就可以不藏精。即使是“春必病温”的话，也是就近指点。总之可见里虚者表不固，一切时邪，都容易感受。学者可因此领悟到四时六气致病的道理。《难经》说：伤寒有五：有伤寒，有中风，有风温，有热病，有湿温。统括这些风寒湿热之邪，而都称之为伤寒的，也是因为早鉴于寒脏受伤，外邪得以进入，所以探究其本源，而都称之为伤寒。大致西北风高土燥，风寒之为病居多；东南地界水湿，湿热之伤人独甚。从来风寒伤形，伤形者一定从表入；湿热伤气，伤气者不一定全从表入。风邪外束，就叫作风温；湿邪内侵，就叫作湿温；纵有微寒的兼袭，不同于凛冽的严威，因此发表宜用辛凉，不宜辛热；清里宜泄热，不宜逐热。如果一概投以发表不远热，攻里不远寒诸法，那么死亡接踵而至了。
Wind, summerheat (Shu), dampness, dryness, and cold are the manifestations of the Qi of Heaven and Earth moving through the four seasons. Only summer belongs to Fire, when sunlight is most intense. The *Neijing* states: "When the annual Fire is excessive, blazing summerheat prevails." This explicitly refers to the fire of the scorching sun. However, the warmth in spring, autumn, and winter is nothing but the light and heat of the sun, and thus cannot be called "summerheat." Therefore, Qibo (Xuanqi) added a "Fire" character below the five Qi. Moreover, regarding summerheat, he clearly stated: "In Heaven it is Heat, on Earth it is Fire, its nature is Summerheat." This indicates that summerheat is merely Heat and Fire; the canonical meaning is already profound and clear. The reason why people suffer predominantly from Fire diseases is that wind, cold, summerheat, and dampness can all transform into Fire, and excessive movement of the Five Emotions invariably generates Fire. This is the great source where heavenly Qi and human nature intersect to generate Fire.
Ye (暍) is summerheat. Referring to summerheat disease as Ye is because summerheat disease is attributed to latent cold, named as Zhong Ye (Heatstroke/Summerheat Stroke) when it manifests after the Summer Solstice. To prevent confusion between the two, this is the method of Zhang Zhongjing.
Shaoyang Cold (Shanghan) cannot be resolved without sweating, and favors inducing sweat; Wind Strike (Shangfeng) also cannot be resolved without sweating, but strongly forbids inducing sweat, only permitting the release of the muscle layer (Jie Ji). This difference in treatment between Mahuang Tang (Ephedra Decoction) and Guizhi Tang (Cinnamon Twig Decoction) lies in their differing methods. Warm diseases (Wenbing) also favor resolution through sweating, but strongly forbid forced sweating; they only permit the use of Acrid-Cool herbs to release the muscle layer, while Acrid-Warm herbs must not be used. The subtlety lies in guiding the pathogen outwards. When Ying and Wei, Qi and Blood harmonize, sweat occurs naturally; there is no need to force sweating. However, for Summerheat-Warmth (Shuwen) and Dampness-Warmth (Shiwen), this is not the case. Summerheat cannot be resolved without sweating, and Xiangru (Moslae Herba) can be used to disperse it. After inducing sweat, if profuse sweating continues, one should revert to the Baihu Tang (White Tiger Decoction) method. This is certainly different from the unceasing leakage of sweat in Shanghan or Shangfeng, which requires Guizhi (Cinnamomi Ramulus) and Fuzi (Aconiti Lateralis Radix Praeparata) to protect Yang and consolidate the exterior. One must not repeatedly weaken the exterior, leading to Jue Tuo (cold limbs and collapse). Observing the ancients' approach in the Summerheat category, the prescription of Shengmai San (Pulse-Generating Powder: Renshen, Maidong, Wuweizi) reveals its rationale.
Exogenous pathogens do not exceed the Six Evils (Liu Yin); people's illnesses should be divided according to the Four Qi. Physicians treating Shanghan blindly adhere to established formulas for releasing the exterior and purging the interior, disregarding the harm caused by Acrid-Warm and Bitter-Cold herbs, thereby obscuring the principles of Warm diseases. I, though untalented, have read extensively and suddenly realized the necessity of studying Warm diseases. The *Neijing* says: "If one does not store essence in winter, one will inevitably contract Warm diseases in spring." This implies that during the severe cold of winter, Yang Qi is internalized. If one conforms to the heavenly timing and remains secure, Kidney Qi fills internally, and Mingmen (Gate of Life), acting as the special envoy of Sanjiao (Triple Burner), also consolidates the Cou Li (pores and interstices) and protects the skin and hair. Even during the ascending and dispersing phase of spring, one's True Qi permeates internally and externally, not depleting with the ascending dispersal. Thus, even if exogenous pathogens exist, how can they invade internally? This is how the *Neijing* clarifies the origin of disease. However, it mentions only "not storing essence in winter" and omits other seasons because winter is the time when Water is prosperous, belonging to the transformation of Northern Cold Water. In terms of season, it is Winter; in terms of the person, it is the Kidney. Well water is warm while hard ice forms; Yin is outside and Yang is inside, embodying the meaning of the Kan hexagram. Hence, the statement emphasizes winter, not implying that only winter is suitable for storing essence while other seasons allow neglect. Even the phrase "spring will inevitably see Warm diseases" is a proximal pointer. Ultimately, it shows that those with interior deficiency have insecure exteriors, making them susceptible to all seasonal pathogens. Students can thereby comprehend the diseases caused by the Six Qi of the four seasons. The *Nanjing* states: There are five types of Shanghan: Shanghan, Fengzhong (Wind Strike), Fengwen (Wind-Warmth), Rebing (Heat Disease), and Shiwen (Dampness-Warmth). Grouping these Wind, Cold, Dampness, and Heat pathogens under the name Shanghan is because, early on, it was recognized that when the Cold Zang organs are injured, exogenous pathogens can enter. Thus, investigating the root, they are all called Shanghan. Generally, in the northwest, winds are high and soil is dry, so Wind-Cold diseases are predominant; in the southeast, the terrain is wet, so Damp-Heat harms people particularly severely. Traditionally, Wind-Cold injures the Form (Xing), and injuries to Form always enter from the exterior; Damp-Heat injures Qi, and injuries to Qi do not necessarily enter from the exterior. When Wind pathogen binds the exterior, it is called Fengwen; when Damp pathogen invades internally, it is called Shiwen. Even if slight cold accompanies it, it differs from the biting severity of freezing cold. Therefore, releasing the exterior should use Acrid-Cool, not Acrid-Warm; clearing the interior should drain Heat, not purge Heat aggressively. If one indiscriminately applies methods such as "releasing the exterior without avoiding Heat" and "purging the interior without avoiding Cold," death would follow in succession.