内经论伤寒。而反发热者有三义。有当时即发者。曰人伤于寒。则为病热也。有过时发热者。曰冬伤于寒。春必病
温也。有随时易名者。曰凡病伤寒而成湿者。先夏至日为病温。后夏至日为病暑也。夫病温病暑。当时即病者不必论。
凡病伤寒而成者。其病虽由于冬时之伤寒。而根实种于其人之郁火。内经曰。藏于精者。春不病温。此明冬伤于寒。春
必病温之源。先夏至日为温病。后夏至日为暑病。申明冬不藏精。春必病温之故。夫人伤于寒。则为病热其恒耳。此
至春夏而病者。以其人肾阳有余。好行淫欲。不避寒冷。虽外伤于寒。而阳气足以御之。但知身着寒。而不为寒所病。
然表寒虽不内侵。而虚阳亦不得外散。仍下陷入阴中。故身不知热。而亦不发热。所云阳病者。上行极而下也。冬时行
收藏之令。阳不遽发。寒愈久。则阳愈匿。阳日盛。则阴日虚。若寒日多。而蓄热浅。则阴火应春气而病温。若寒日多
而郁热深。则阴火应夏气而病暑。此阴消阳长。从内而达于外也。叔和不知此义。谓寒毒藏于肌肤。至春变为温病。至
夏变为暑病。夫寒伤于表。得热则散。何以能藏。设无热以御之。必深入腑脏。何以只藏于肌肤。且能藏者不能变。何
以时换其所藏乎。不知原其人之自伤。而但咎其时之外伤。只知伤寒之因。不究热伤其本。妄拟寒毒之能变热。不知内
陷之阳邪。发见其本来面目也。又谓辛苦之人。春夏多温热病者。皆因冬时触寒所致。而非时行之气。不知辛苦之人。
动摇筋骨。凡动则为阳。往往触寒即散。或因饥寒而病者有之。或因劳倦而发热者有之。故春夏之时。辛苦之人。因虚
而感时行之气者不少矣。若夫春夏之湿热。由冬时触寒所致者。偏在饱暖淫欲之人。不知持满醉以入房。以竭其精。以
耗其真。阳强不能密。精失守而阴虚。故移祸至于春夏也。内经论温之脉症治法甚详。学人多不得要领。仲景独挈发
热而渴。不恶寒者为提纲。悉温病之底蕴。合内经冬不藏精之旨矣。热论以口燥舌干而渴属少阴。少阴者封蛰之本。
精之处也。少阴之表。名曰太阳。太阳根起于至阴。名曰阴中之阳。故太阳病。当恶寒。此发热而恶寒者。是阳中无阴
矣。而即见少阴之渴。太阳之根本悉露矣。于此见逆冬气。则少阴不藏。肾气独沉。孤阳无时而发为温病也。温病症治。
散见六经。请类推之。如伤寒发热不渴。服汤已渴者。是伤寒温病之关也。寒去而热罢。即伤寒欲解症。寒去而热不解。
是温病发见矣。如服桂枝汤。大汗出后。大烦渴不解。脉洪大者。即是温势猖狂。用白虎加人参预保元气于清火之时。
是凡病伤寒而成温者之正治法也。因所伤之寒邪随大汗而解。所成之温邪随大汗而发。焉得无虚。设不加参。则热邪从
白虎而解。安保寒邪不从白虎而来乎。是伤者当补。治病必求其本耳。如服柴胡渴已。渴者属阳明者也。以法治之。夫
柴
胡汤有参甘姜枣。皆生津之品。服已反渴。是服寒之剂。不足以解温邪。少阳相火直走阳明也。是当白虎加人参法。若
柴胡加人参之法。非其治矣。夫相火寄甲乙之间。故肝胆为发温之源。腹胃为市。故阳明为成温之薮。阳明始虽恶寒。
二日自止。即不恶寒。而反恶热。此亦病伤寒而成温之一征也。若夫温热不因伤寒而致者。只须扶阴折阳。不必补中益
气矣。且温邪有浅深。治法有轻重。如阳明病。脉浮发热。渴欲饮水。小便不利者。猪苓汤主之。瘀热在里不得越。身体发黄。渴欲饮水。小便不利者。茵陈汤主之。少阴病。得之二三日。口燥咽干者。大承气汤急下之。厥阴病下利欲饮水者。白头翁汤主之。此仲景治温之大略也。夫温与暑。偶感天气而病者轻。因不藏精者。为自伤其病重。若再感方土之异气。此三气相合而成温疫也。温热利害。只在一人。温疫移害。祸延邻里。今人不分温热温疫。浑名温病。令人恶闻而讳言之。因于辞之害义矣。吴又可温疫论。程效倩热病注。俱有至理可传。愚不复赘。余义详见方论。
The *Neijing* (Inner Canon) discusses cold damage, mentioning three meanings for cases where fever occurs instead. One is immediate onset: "When a person is injured by cold, it becomes a disease of heat." Another is delayed onset: "If injured by cold in winter, one will surely suffer from warm disease in spring." The third involves changing names with the seasons: "For those who contract cold damage and develop dampness, if it occurs before the Summer Solstice, it is called warm disease; if after the Summer Solstice, it is called summerheat disease." Cases of warm or summerheat disease occurring immediately upon infection are not discussed here.
For diseases evolving from cold damage, although the cause originates from winter cold, the root actually lies in the person's internal stagnant fire. The *Neijing* states: "Those who store essence [Jing] will not suffer from warm disease in spring." This clarifies the source of "injured by cold in winter, causing warm disease in spring." Warm disease refers to onset before the Summer Solstice, and summerheat disease to onset after it, explaining why failure to store essence in winter leads to illness in spring.
Generally, injury by cold results in heat disease. However, illnesses manifesting in spring and summer occur because the individual has excess Kidney Yang, engages in sexual activity excessively, and fails to avoid cold. Although externally injured by cold, the internal Yang is sufficient to resist it; thus, they feel cold but are not harmed by the cold pathogen. Yet, since the exterior cold cannot penetrate inward, the deficient Yang cannot disperse outward and sinks into the Yin. Consequently, there is no sensation of heat and no fever. This is described as "Yang diseases, when rising to the extreme, descend." In winter, the command of storage prevails, and Yang does not suddenly emerge. The longer the cold persists, the more hidden the Yang becomes; as Yang increases daily, Yin decreases daily. If cold exposure is prolonged but accumulated heat is shallow, the Yin fire responds to Spring Qi and causes warm disease. If cold exposure is prolonged and deep stagnation of heat exists, the Yin fire responds to Summer Qi and causes summerheat disease. This represents the decline of Yin and growth of Yang, extending from the interior to the exterior.
Wang Shuhe misunderstood this principle, claiming that cold toxin hides in the skin and muscles, transforming into warm disease in spring and summerheat disease in summer. Cold injuring the exterior should dissipate with heat; how can it hide? Without heat to resist it, cold would deeply invade the Zang-Fu organs, not just remain in the skin and muscles. Moreover, what hides cannot change its nature; why does it transform over time? He failed to recognize self-injury, blaming only external seasonal factors. He knew the cause of cold damage but ignored the root injury caused by heat. He wrongly speculated that cold toxin transforms into heat, failing to realize that the internally sinking Yang pathogen reveals its true nature.
He also stated that hardworking people often suffer warm-heat diseases in spring and summer due to winter cold exposure, rather than epidemic Qi. He did not understand that hardworking individuals move their bones and sinews; movement generates Yang, so cold encountered during activity usually disperses. Some fall ill due to hunger and cold, others due to fatigue and fever. Thus, in spring and summer, many hardworking people contract epidemic Qi due to deficiency. Regarding damp-heat in spring and summer caused by winter cold, this applies mainly to those who are well-fed, sedentary, and indulgent. They fail to preserve fullness, engage in intercourse while drunk, depleting essence and exhausting true Yuan Qi. Their Yang becomes strong but unconsolidated, leading to loss of essence and Yin deficiency, with disasters manifesting in spring and summer.
The *Neijing* details the pulse, symptoms, and treatments for warm diseases, yet students often miss the key points. Zhang Zhongjing uniquely extracted "fever with thirst and aversion to cold absent" as the guiding principle, revealing the essence of warm disease and aligning with the *Neijing*'s teaching on failing to store essence in winter. The *Treatise on Cold Damage* attributes dry mouth and tongue with thirst to the Shaoyin channel. Shaoyin is the root of sealing and storing, the residence of essence. Its exterior counterpart is Taiyang. Taiyang originates at Yongquan (KI1), known as Yang within Yin. Therefore, Taiyang disease typically presents with aversion to cold. Fever with aversion to cold here indicates a lack of Yin within Yang (Yang without Yin), accompanied by Shaoyin-type thirst, exposing the fundamental disorder of Taiyang. This shows that violating winter storage leads to Shaoyin failing to store, Kidney Qi sinking alone, and isolated Yang erupting as warm disease.
Symptoms and treatments of warm diseases are scattered across the Six Channels; please infer accordingly. For instance, cold damage with fever but no thirst, followed by thirst after medication, marks the transition between cold damage and warm disease. If cold leaves and heat subsides, it is the resolution of cold damage. If cold leaves but heat persists, warm disease has manifested. For example, after taking Guizhi Tang (Cinnamon Twig Decoction), profuse sweating leads to severe restlessness, unrelenting thirst, and a flooding pulse. This indicates rampant warm pathogens. Using Baihu Jia Renshen Tang (White Tiger Plus Ginseng Decoction) protects primordial Qi while clearing fire, which is the correct treatment for cold damage evolving into warm disease. The cold pathogen resolves with sweat, but the generated warm pathogen emerges with sweat, causing deficiency. Without Ginseng, although heat clears via White Tiger, how can we ensure cold does not enter? Injury requires tonification; treating disease must address the root.
If, after taking Chaihu Tang (Bupleurum Decoction), thirst ceases then returns, it belongs to the Yangming channel. Treat accordingly. Chaihu Tang contains Renshen (Ginseng Root), Gancao (Licorice Root), Shengjiang (Fresh Ginger), and Dazao (Jujube Fruit), all generating fluids. Returning thirst after taking this cold-natured formula indicates insufficient power to resolve warm pathogens, as Shaoyang Ministerial Fire moves directly to Yangming. Baihu Jia Renshen Tang is indicated; using Chaihu Jia Renshen Tang is inappropriate. Ministerial Fire resides between Jia and Yi (Liver/Gallbladder), making Liver and Gallbladder the source of warm disease. Spleen and Stomach are the market, making Yangming the gathering place of warm disease. Yangming disease may initially have aversion to cold, which stops by day two. Even without aversion to cold, aversion to heat appears, another sign of cold damage evolving into warm disease.
For warm-heat diseases not caused by cold damage, merely support Yin and subdue Yang; middle-tonifying and Qi-supplementing methods are unnecessary. Warm pathogens vary in depth, requiring graded treatments. For Yangming disease with floating pulse, fever, thirst for water, and difficult urination, Zhu Ling Tang (Polyporus Decoction) is primary. For stasis-heat trapped inside causing jaundice, thirst for water, and difficult urination, Yinchen Tang (Artemisia Capillaris Decoction) is primary. For Shaoyin disease presenting with dry mouth and throat within two to three days, Dachengqi Tang (Major Order the Qi Decoction) is used for urgent purgation. For Jueyin disease with diarrhea and desire for water, Baitouweng Tang (Pulsatilla Decoction) is primary. These are Zhang Zhongjing’s general principles for treating warm diseases.
Warm and summerheat diseases contracted incidentally from weather are mild; those due to failing to store essence are severe self-injury. If combined with local abnormal Qi, these three factors create epidemic warm disease. The harm of warm/heat diseases affects an individual; epidemic warm diseases spread to neighbors. Modern people confuse warm/heat with epidemic warm disease, labeling all as "warm disease," causing aversion and silence, harming meaning through terminology. Wu Keyi’s *Treatise on Epidemic Warmth* and Cheng Xiaoqian’s *Annotations on Heat Diseases* contain profound truths worth transmitting; I add nothing further. Remaining details are in the formula discussions.