伤寒初得宜用热药发其汗，麻黄、桂枝诸汤是也。风温初得宜用凉药发其汗，薄荷、连翘、蝉蜕诸药
是也。至传经已深，阳明热实，无论伤寒、风温，皆宜治以白虎汤。而愚用白虎汤时，恒加薄荷少许，或连
翘、蝉蜕少许，往往服后即可得汗。即但用白虎汤，亦恒有服后即汗者。因方中石膏原有解肌发表之力，故
其方不但治阳明府病，兼能治阳明经病，况又少加辛凉之品引之，以由经达表，其得汗自易易也。拙
拟寒解汤后载有医案可参
阅。该方原治寒温证周身壮热，心中热而且渴，舌苔白而欲黄，其脉洪滑或兼浮，或头犹觉疼，或周身犹有
拘束之意者。果如方下所注证脉，服之复杯可汗，勿庸虑其不效也。盖脉象洪滑，阳明府热已实，原是
白虎汤证。至洪滑兼浮，舌苔犹白，是仍有些些表证未罢。故方中重用石膏、知母以清胃府之热，复少用
连翘、蝉蜕之善达表者，引胃中化而欲散之热仍还于表，作汗而解。斯乃调剂阴阳，听其自汗，非强发其汗也。
至其人气体弱者，可用补气之药助之出汗。寒解汤加潞党参即可（寒解汤下载有治一叟年七旬，素有劳疾，
薄受外感即发喘逆一案可参阅）。
若阴分虚损者，可用滋阴之药助之出汗。若熟地、玄参、生
山药、枸杞之类大润之剂峻补真阴，济阴以应其阳，设病有还表之机，必汗出而愈。
至其人阳分阴分俱虚，又宜并补其阴阳以助之出汗。张景岳曾治一叟得伤寒证，战而不汗。于其翌日
发战之时，投以大剂八味地黄汤，须臾战而得汗。继因汗多亡阳，身冷汗犹不止，仍投以原汤，汗止病亦遂
愈。用其药发汗，即用其药止汗，是能运用古方入于化境者也。
至少阳证为寒热往来，其证介于表里之间，宜和解不宜发汗矣。然愚对于此证，其热盛于寒者，多因
证兼阳明，恒于小柴胡汤中加玄参八钱，以润阳明之燥热。其阳明之燥热化而欲散，自能还于太阳而作汗，
少阳之邪亦可随汗而解。其寒盛于热者，或因误服降下药虚其气分，或因其气分本素虚，虽服小柴胡汤不能
提其邪透膈上出，又恒于小柴胡汤中加薄荷叶二钱，由足少阳引入手少阳，借径于游部（手足少阳合为游部）
作汗而解。此即《伤寒论》所谓“柴胡证具，而以他药下之，柴胡证仍在者，复与小柴胡汤，必
蒸蒸而振，却发热汗出而解也。”然助以薄荷则出汗较易，即由汗解不必蒸蒸而振，致有战汗之状也。
至于当用承气之证，却非可发汗之证矣。然愚临证经验以来，恒有投以三承气汤，大便犹未降下而即得
汗者。盖因胃府之实热既为承气冲开，其病机自外越也。若降之前未尝得汗，既降之后亦必于饮食之时屡
次些些得汗，始能脉净身凉。若降后分毫无汗，其热必不能尽消，又宜投以竹叶石膏汤，或白虎加人参
汤，将其余热消解将尽，其人亦必些些汗出也。此所谓伤寒、风温始终皆宜汗解也。
伤寒初起适宜使用热性药物来发汗，麻黄汤、桂枝汤等方剂就是此类。风温初起适宜使用凉性药物来发汗，薄荷、连翘、蝉蜕等药材就是此类。到了病邪传入经络已深，出现阳明经腑实热的情况，无论是伤寒还是风温，都适宜用白虎汤治疗。而我在使用白虎汤时，常常加入少许薄荷，或者少许连翘、蝉蜕，往往服用后随即就能出汗。即使单用白虎汤，也常有服用后即出汗的情况。因为方中的石膏原本就有解除肌表邪气、透发表邪的作用，所以这个方子不仅能治疗阳明腑病，兼也能治疗阳明经病，何况又少量加入辛凉性质的药物作为引导，使邪气由经达表，其出汗自然容易得很。我在《寒解汤》后附有医案可供参考。该方原用于治疗寒温证患者周身壮热，心中烦热且口渴，舌苔白而欲变黄，脉象洪大滑数或兼浮象，或者头部仍觉疼痛，或者周身仍有拘束不适感的情况。如果确实符合方下所注的证候和脉象，服用后片刻即可出汗，无需担心无效。因为脉象洪大滑数，说明阳明腑热已经结实，这原本是白虎汤的适应证。至于脉象洪大滑数兼见浮象，舌苔仍然发白，说明仍有些许表证未除。因此方中重用石膏、知母以清泻胃腑之热，再少用善于透达肌表的连翘、蝉蜕，引导胃中化散欲出的热邪仍返还于体表，通过出汗而解除。这是调和阴阳，听任其自然出汗，并非强行发汗。
对于体质虚弱的人，可以使用补气药物辅助其出汗。在寒解汤中加入潞党参即可（寒解汤下载有一则治疗一位七十岁老人，素有劳损疾病，轻微受外感即引发喘逆的医案可供参考）。如果是阴分虚损的人，可以使用滋阴药物辅助其出汗。如熟地黄、玄参、生山药、枸杞子等大滋润的药物峻补真阴，济助阴液以顺应阳气，假如病邪有回归体表的转机，必然通过出汗而痊愈。
对于阴阳两虚的人，又适宜同时补益阴阳以辅助其出汗。张景岳曾治疗一位老人患伤寒证，身体战栗但不出汗。在第二天发作战栗时，投以大剂量的八味地黄汤，片刻之后战栗并得出汗。随后因出汗过多导致亡阳，身体冷汗不止，仍然投以原方，汗止病也随之痊愈。用这些药来发汗，也用这些药来止汗，这是能灵活运用古方达到化境的人。
至于少阳证表现为寒热往来，此证介于表里之间，适宜和解而不适宜发汗。然而我对此证，若热盛于寒者，多因证候兼夹阳明病，常在柴胡汤中加入玄参八钱，以润燥清泄阳明之热。阳明之燥热化解欲散，自然能返还于太阳经而作汗，少阳之邪也可随汗而解。若寒盛于热者，或因误服降下药损伤了气分，或因其气分本来素虚，虽然服用柴胡汤不能提举邪气透膈上行外出，常在柴胡汤中加入薄荷叶二钱，由足少阳经引入手少阳经，借道于游部（手足少阳合称为游部）作汗而解。这就是《伤寒论》所说的“柴胡证具备，却用其他药物攻下，柴胡证仍在的，再给予小柴胡汤，必定会蒸蒸发热而振栗，随后发热出汗而解。”然而借助薄荷则出汗较为容易，即使由汗而解也不必出现蒸蒸振栗的战汗状态。
至于应当使用承气汤类的证候，却不是可以发汗的证候了。然而我临证经验以来，常有投予三承气汤，大便尚未通下而随即出汗的情况。这是因为胃腑的实热既被承气汤冲开，病机自然向外发散。如果在攻下之前未曾出汗，攻下之后也必会在饮食之时屡次微微出汗，才能使脉象清净、身体凉爽。如果攻下后分毫无汗，其热势必然不能完全消退，又适宜投予竹叶石膏汤，或白虎加人参汤，将其余热消解将尽，其人也会微微出汗。这就是所谓伤寒、风温始终都适宜通过汗法来解除的道理。
In the initial stage of Shanghan (Cold Damage), it is appropriate to use hot-natured medicines to induce sweating, such as formulas like Mahuang Tang (Ephedra Decoction) and Guizhi Tang (Cinnamon Twig Decoction). In the initial stage of Fengwen (Wind-Warmth), it is appropriate to use cool-natured medicines to induce sweating, such as herbs like Bohe (Menthae Haplocalycis Herba), Lianqiao (Forsythiae Fructus), and Chantui (Cicadae Periostracum). When the pathogen has transmitted deeply into the meridians, resulting in Yangming excess-heat and solidification, whether it is Shanghan or Fengwen, it is appropriate to treat with Baihu Tang (White Tiger Decoction). However, when I use Baihu Tang, I often add a small amount of Bohe, or a small amount of Lianqiao and Chantui, and patients often sweat immediately after taking it. Even when using only Baihu Tang, sweating frequently occurs after administration. This is because Shigao (Gypsum Fibrosum) in the formula originally possesses the power to release the muscle layer and expel pathogens from the exterior. Therefore, this formula not only treats Yangming Fu-organ disease but also addresses Yangming Meridian disease. Moreover, by adding a small amount of acrid-cool substances to guide the pathogen from the meridian to the surface, inducing sweat becomes very easy. Medical cases recorded after Hanjie Tang (Cold-Resolving Decoction) can be consulted for reference. This formula was originally designed to treat Cold-Warmth syndromes characterized by high fever throughout the body, heat and thirst in the heart, a white tongue coating turning yellow, a surging and slippery pulse possibly accompanied by floating, headache, or a sensation of stiffness throughout the body. If the symptoms and pulse match those noted under the formula, sweating will occur within a short time after ingestion; there is no need to worry about inefficacy. A surging and slippery pulse indicates that Yangming Fu-organ heat is already solidified, which is indeed an indication for Baihu Tang. When the surging and slippery pulse is accompanied by floating, and the tongue coating remains white, it signifies that some exterior syndrome has not yet resolved. Thus, the formula heavily uses Shigao and Zhimu (Anemarrhenae Rhizoma) to clear the heat of the Stomach Fu, while employing small amounts of Lianqiao and Chantui, which are good at reaching the exterior, to guide the heat generated in the Stomach back to the surface to be resolved through sweating. This adjusts Yin and Yang, allowing natural sweating, rather than forcibly inducing sweat.
For individuals with weak constitution, Qi-tonifying medicines can be used to assist in sweating. Adding Lupangshen (Codonopsis Radix) to Hanjie Tang is sufficient (a case treating a seventy-year-old man with chronic fatigue who developed wheezing upon slight external contraction is recorded under Hanjie Tang for reference). For those with deficiency damage in the Yin aspect, Yin-nourishing medicines can be used to assist sweating. Large moistening agents such as Shudi (Rehmanniae Radix Preparata), Xuanshen (Scrophulariae Radix), Sheng Shanyao (Dioscoreae Rhizoma), and Gouqi (Lycii Fructus) can severely tonify True Yin, nourishing Yin to support Yang. If there is a tendency for the pathogen to return to the exterior, recovery will inevitably occur through sweating.
For individuals with deficiency in both Yin and Yang aspects, it is appropriate to tonify both Yin and Yang simultaneously to assist sweating. Zhang Jingyue once treated an elderly man suffering from Shanghan who shivered but did not sweat. On the following day during his shivering episode, he administered a large dose of Bawei Dihuang Tang (Eight-Ingredient Rehmannia Decoction), after which shivering ceased and sweating occurred. Subsequently, due to excessive sweating leading to Yang collapse, cold sweat continued unabated; he still administered the original decoction, after which sweating stopped and the illness resolved. Using these medicines to induce sweat and using them to stop sweat demonstrates the ability to apply ancient formulas with mastery.
Shaoyang syndrome is characterized by alternating chills and fever, lying between the exterior and interior, making harmonization appropriate rather than sweating. However, regarding this syndrome, when heat exceeds cold, it is often due to concurrent Yangming involvement. I frequently add eight qian of Xuanshen to Xiaochaihu Tang (Minor Bupleurum Decoction) to moisten and clear Yangming dryness-heat. As the dryness-heat of Yangming resolves and disperses, it naturally returns to Taiyang to produce sweat, and Shaoyang pathogens can also be resolved through sweat. When cold exceeds heat, it may be due to previous misuse of purgatives damaging Qi, or inherent Qi deficiency. Although Xiaochaihu Tang is taken, it may fail to lift the pathogen above the diaphragm for expulsion. In such cases, I often add two qian of Bohe Ye (Menthae Haplocalycis Folium) to Xiaochaihu Tang, guiding the pathogen from Foot-Shaoyang to Hand-Shaoyang, utilizing the Youbu (Wandering Department, where Hand and Foot Shaoyang merge) to induce sweating. This corresponds to the statement in Shanghan Lun: "When Chaihu syndrome is present, if other medicines were mistakenly used to purge, and Chaihu syndrome persists, administering Xiaochaihu Tang again will cause steaming heat and trembling, followed by fever and sweating for resolution." However, assisting with Bohe makes sweating easier, avoiding the steaming and trembling associated with Zhanhan (Battle Sweat).
Regarding indications for Chengqi Tangs, these are not conditions suitable for inducing sweat. However, in my clinical experience, patients often sweat immediately after administering San Chengqi Tangs (Three Purging Formulas), even before bowel movements occur. This is because once the excess heat in the Stomach Fu is broken open by the Chengqi formulas, the pathological mechanism naturally moves outward. If sweating had not occurred before purgation, slight sweating will likely occur repeatedly during meals after purgation, until the pulse clears and the body cools. If no sweating occurs after purgation, the heat cannot fully dissipate; in such cases, Zhuye Shigao Tang (Bamboo Leaf and Gypsum Decoction) or Baihu Jia Renshen Tang (White Tiger Decoction plus Ginseng) should be administered to resolve residual heat, after which the patient will likely sweat slightly. This illustrates why Shanghan and Fengwen should always be resolved through sweating.