内经黄帝问曰。今夫热病者。皆伤寒之类也。岐伯对曰。人之伤于寒也。则为病热。热虽甚。不死。黄帝又问曰。
人伤于寒而传为热。何也。岐伯曰。夫寒甚。则生热也。此可见人病伤寒。皆系热证。或疑其所伤非热。要其寒气既传
于内。无有不郁而生热者。故人之热病虽多。惟伤寒之热。其热为最。方寒之初感也。扪其人之头额肢体。其肌肤烙手
而热如火。及寒之深入也。候其人之口鼻呼吸。其出气熏人而热如蒸。甚则面红目赤。鼻干唇焦。齿燥舌裂。喜露手足。
裸身体。渴欲饮水。溺浊而赤。便焦而黑。凡人身表里上下。无处非热。又何有于寒哉。内经中论伤寒。反以热病名篇。
即此意也。难经云。伤寒有五。有中风。有伤寒。有湿温。有热病。有温病。凡风湿温热。皆得谓之伤寒。则知其名虽
为寒。其实非真寒也。汉张仲景着伤寒论。凡温暑风湿疟痢。时行疫毒之气。多杂其中。其意何也。彼盖以以上等证。
皆系热病。人患热病。多传经。故凡传经之热病。经云皆伤寒之类也。其论中所不解者。三阴经真寒证。不由阳经传入。
并非内经所云热病。亦列于传经热病之中。使后之学人。寒热不明。阴阳错误。其为害可胜道哉。金时刘河间集伤寒标
本一书。只分汗下和解法。置温中之例不论。其于麻桂等汤中。类加知母石膏黄芩等药。更于柴胡白虎承气等汤外。复
制天水散。凉膈散。甘露饮。解毒汤等。辄投以三黄三石等。苦寒甘辛凉解之药。至仲景所用干姜乌附桂心吴茱萸等汤
剂。并未言及。此岂患病之人。再无阴寒之证者邪。但既曰伤寒。皆是热病。当如内经中所云也。自丹溪朱氏出。始云
仲景论伤寒矣。而未及乎中寒。曰伤曰中。不闻有议。愚今祖丹溪之意。凡仲景中寒之条。混于伤寒中者。悉为标出。
另作一书。名曰中寒论。其余温暑诸病。虽各因证分别。要其病名。皆曰伤寒。何也。以其病皆热病。皆传经者也。爰
集古今诸名家之说。附以管见。为着伤寒非寒论。其中间有缺略。当俟后之君子。起而补辑之。
In the *Huangdi Neijing* (Yellow Emperor's Inner Canon), the Yellow Emperor asked, "Nowadays, febrile diseases are all of the category of Shanghan (Cold Damage)." Qibo replied, "When humans are injured by cold pathogens, they develop febrile diseases. Even if the heat is severe, it will not be fatal." The Yellow Emperor then asked, "Why does injury by cold transform into heat?" Qibo said, "When cold is extreme, it generates heat." This shows that when humans contract Shanghan, it manifests as a heat syndrome. Some may doubt that the pathogen is not heat, but once the cold qi transmits inward, it inevitably stagnates and generates heat. Therefore, although there are many types of febrile diseases, the heat from Shanghan is the most intense. At the initial stage of cold contraction, touching the patient's forehead and limbs reveals skin that burns to the touch, hot as fire. As the cold penetrates deeply, observing the patient's nasal and oral respiration reveals exhaled air that is scorching, like steam. In severe cases, the face turns red, eyes become congested, the nose is dry, lips are cracked, teeth are dry, and the tongue splits. Patients prefer to expose their limbs and bare their bodies, feel thirsty and desire water, have turbid and dark-red urine, and pass dry, black stools. Everywhere on the body—interior, exterior, upper, and lower—is filled with heat; where is there any cold? In the *Neijing*, discussions on Shanghan are instead titled under 'Febrile Diseases,' which reflects this meaning.
The *Nan Jing* (Classic of Difficult Issues) states: "Shanghan comprises five types: Zhongfeng (Wind Strike), Shanghan, Shiwen (Damp-Warmth), Rebing (Febrile Disease), and Wenbing (Warm Disease). All wind, damp, warm, and heat pathogens can be termed Shanghan." Thus, although named 'cold,' it is actually not true cold. Zhang Zhongjing of the Han Dynasty authored the *Shanghan Lun* (Treatise on Cold Damage), in which he mixed conditions such as Warm diseases, Summerheat diseases, Wind-Dampness, Malaria, Dysentery, and epidemic toxic qi. What was his intent? These aforementioned syndromes are all febrile diseases. Humans suffering from febrile diseases often undergo meridian transmission. Therefore, all febrile diseases that transmit through meridians are categorized under Shanghan in the *Neijing*. However, there are inexplicable aspects in the *Shanghan Lun*: the True Cold syndromes of the Three Yin Meridians do not transmit from the Yang meridians nor are they the febrile diseases mentioned in the *Neijing*, yet they are listed among the transmitted febrile diseases. This causes later scholars to confuse cold and heat, and err in distinguishing Yin and Yang, a harm that cannot be overstated.
During the Jin Dynasty, Liu Hejian compiled the *Shanghan Biaoben* (Roots and Branches of Shanghan), classifying only Sweating (Han), Purging (Xia), and Harmonizing methods, while omitting Warming-Middle methods. He added herbs such as Zhi Mu (Anemarrhenae Rhizoma), Shigao (Gypsum Fibrosum), and Huang Qin (Scutellariae Radix) to formulas like Mahuang Tang (Ephedra Decoction) and Guizhi Tang (Cinnamon Twig Decoction). Beyond formulas like Chaihu Tang (Bupleurum Decoction), Baihu Tang (White Tiger Decoction), and Chengqi Tang (Order the Qi Decoction), he additionally prepared Tianshui San (Heavenly Water Powder), Liangge San (Cooling Diaphragm Powder), Ganlu Yin (Sweet Dew Drink), and Jiedu Tang (Detoxification Decoction), frequently administering bitter-cold, sweet-pungent, or cooling-resolving agents like Sanhuang Sanshi (Three Yellows and Three Stones). Yet, he did not mention the decoctions used by Zhang Zhongjing containing Ganjiang (Zingiberis Rhizoma), Wutou (Aconiti Radix), Fuzi (Aconiti Lateralis Radix Praeparata), Guixin (Cinnamomi Ramulus), or Wuzhuyu (Evodiae Fructus). Could it be that patients no longer present with Yin-Cold syndromes? If Shanghan is indeed all febrile disease, it should align with the descriptions in the *Neijing*.
Since Zhu Danxi appeared, it was claimed that Zhang Zhongjing discussed Shanghan but omitted Zhonghan (Middle Cold). There was no discussion regarding the distinction between 'Shang' (injury) and 'Zhong' (strike). Following Danxi's intent, I now identify all clauses in Zhang Zhongjing's work concerning Zhonghan that are mixed within Shanghan, marking them separately to create a new book titled *Zhonghan Lun* (Treatise on Middle Cold). Other diseases such as Warm and Summerheat diseases, though distinguished by symptoms, are all named Shanghan. Why? Because these diseases are all febrile and involve meridian transmission. I have collected the theories of ancient and modern masters, appended my own insights, and composed this *Shanghan Feihan Lun* (Treatise on Shanghan Not Being Cold). Any omissions herein shall await future scholars to supplement and edit.