赵嗣真曰∶按仲景论，谓冬月冒寒，伏藏于肌肤，而未即病，因春温气所变，则为热。夫变者，改易之义也。至此，
则伏寒各随春夏之气，改变为温为热，既变之后，不得复言其为寒也。所以仲景云温病不恶寒者，其理可见矣。《活人
书》其于温病曰∶阳热未盛，为寒所制，岂有伏寒既已变而为温，尚可言寒能制其阳热耶！又于热病曰∶阳热已盛，寒
不能制，亦不当复言其为寒也。盖是春夏阳热已变，其伏寒即非有寒，能制其阳热尔。外有寒邪能折阳气者，乃是时行
寒疫，仲景所谓∶春分以后，秋分节前，天有暴寒，为时行寒疫是也。三月、四月，其时阳气尚弱，为寒所折，病热则
轻；五月、六月，阳气已盛，为寒所折，病热则重；七月、八月，阳气已衰，为寒所折，病热亦微。是知时行寒疫，与
温热二病，所论阳气盛衰，时月则同。至于论暴寒之寒，与伏寒已变之寒，自是相违，名不正，则言不顺矣。仲景又云∶
其病与温及暑病相似，但治有殊耳。要在辨其病源寒热温三者之殊，则用药之冷热判然矣。（《伤寒琐言·伤寒变温热病
论》）
（一）至春分节后，天令温暖，有人壮热为病者。乃温病也。《经》云∶冬伤于寒，发为温病。又云∶太阳病发热
而渴，不恶寒者为温病。言冬时伏气，随时温热发出，但所发之因不同，有感非时暴寒而发者；有饥饱劳役而发者；有
房室作力而发者。所感之客邪既殊，发出之经络亦异，所谓温病之脉，行在诸经，不知何经之动也，当随其经证而治之。
凡温病之发，必大渴烦扰，胁满口苦，不恶寒反恶热，脉气口反盛于人迎，明系伏邪自内达表，必先少阳经始。（《温病》）
（二）大抵治温病、热病，无正发汗之理。盖其邪自内达外，无表证明矣。若果证显非时暴寒，恶寒头痛，而脉浮
紧者，亦不可纯用表药。（《温病》）
（三）大抵温病热病，皆是热郁之气，故多发于三阳。若发于三阴者，必难治。其脉若沉细，或微弱，或虚大无力，
为脉不应病，必死。然发于三阴者，必有所因，或因冷食伤脾，或因欲事伤肾，皆正气先伤，热毒乘虚而发，设用甘温
调补，宁不助邪转炽。若行苦寒峻攻，真元立致消亡，虽长沙、河间复起，恐难为力矣。（《热病》）
赵嗣真说：考察张仲景的论述，认为冬季感受寒邪，潜伏在肌肤之间，并没有立即发病，到了春季因为温气的变化，就转化为热证。所谓“变”，就是改易的意思。到了这个时候，潜伏的寒邪各自随着春夏季节的气候，改变为温病或热病，既然已经转变，就不能再说它是寒邪了。所以张仲景说温病不恶寒，其中的道理就可以明白了。《活人书》对于温病的论述说：阳热还没有旺盛，被寒邪所制约，难道潜伏的寒邪既然已经转变为温病，还能说寒能制约它的阳热吗！又在热病的论述中说：阳热已经旺盛，寒不能制约，也不应当再说它是寒邪了。这是因为春夏季节阳气热势已经转变，潜伏的寒邪就不再具有寒性，能够制约阳热罢了。另外有寒邪能够折损阳气的情况，那是时行寒疫，就是张仲景所说的：春分以后，秋分以前，天气突然寒冷，称为时行寒疫。三月、四月，此时阳气还较弱，被寒邪折损，患病发热则较轻；五月、六月，阳气已经旺盛，被寒邪折损，患病发热则较重；七月、八月，阳气已经衰退，被寒邪折损，患病发热也轻微。由此可知，时行寒疫与温热两类疾病，所讨论的阳气盛衰、月份是相同的。至于论述突发寒邪的寒，与潜伏寒邪已转变的寒，自然是相互违背的，名称不正确，言语就不顺理成章。张仲景又说：这种病与温病及暑病相似，但治疗方法不同。关键在于辨别病源中寒、热、温三者的区别，那么用药的冷与热就截然分明了。（出自《伤寒琐言·伤寒变温热病论》）
（一）到了春分节气之后，天气温暖，有人出现高热症状而生病的。这是温病。《内经》说：冬季受寒，发作成为温病。又说：太阳病（太阳经受邪所致的病证）发热且口渴，不恶寒的是温病。说的是冬季潜伏的邪气，随着时令的温热而发出，只是发出的原因不同，有的因感受非时节的暴寒而发作；有的因饥饱失调、劳累过度而发作；有的因房事用力而发作。所感受的外邪既然不同，发出的经络也不同，所谓温病的脉象，运行在诸条经脉中，不知道是哪条经脉发生变动，应当根据该经的症状来治疗。凡是温病发作，必定大渴、烦躁扰攘，胁肋胀满、口苦，不恶寒反而恶热，脉象寸口反比人迎脉盛大，这明显是伏邪从内部达于体表，必定先从少阳经开始。（出自《温病》）
（二）大抵治疗温病、热病，没有正发汗的道理。因为邪气从内部达于外部，没有表证是明确的。如果确实症状显现为非时节的暴寒，恶寒头痛，且脉象浮紧，也不可单纯使用解表药物。（出自《温病》）
（三）大抵温病和热病，都是热郁结之气，所以多发生于三阳经。如果发生于三阴经，必定难以治疗。其脉象如果沉细，或微弱，或虚大无力，属于脉象与病症不符，必定死亡。然而发生于三阴经的，必定有其原因，或因冷食损伤脾脏，或因房事损伤肾脏，都是正气先受损，热毒乘虚而发，如果使用甘温调补的方法，岂不是助长邪气更加炽盛？如果施行苦寒峻猛攻下，真元立刻导致消亡，即使是张仲景、刘完素再生，恐怕也难以奏效了。（出自《热病》）
Zhao Sizhen stated: Examining Zhang Zhongjing's treatise, it is said that in winter, one contracts cold pathogens which lie dormant in the skin and muscles without causing immediate illness. When spring warmth arrives, this latent condition transforms into heat. The term "transform" (bian) implies alteration or change. At this stage, the latent cold follows the qi of spring and summer, transforming into warm diseases or heat diseases. Once transformed, it can no longer be referred to as cold. Thus, Zhang Zhongjing's statement that warm diseases do not present with aversion to cold becomes understandable.
The *Huoren Shu* (Book of Living People), regarding warm diseases, states: "When yang-heat is not yet abundant, it is constrained by cold." How could it be said that if latent cold has already transformed into warmth, cold could still constrain its yang-heat? Furthermore, regarding heat diseases, it states: "When yang-heat is already abundant, cold cannot constrain it," implying it should no longer be described as cold. This is because during spring and summer, yang-heat has already transformed, and the latent cold no longer possesses the nature of cold to constrain yang-heat.
However, there are cases where external cold pathogens damage yang-qi; these are termed seasonal cold epidemics (shixing hanyi). This corresponds to Zhang Zhongjing's description: "After the Spring Equinox and before the Autumn Equinox, sudden cold weather constitutes a seasonal cold epidemic." In March and April, when yang-qi is still weak, if damaged by cold, the resulting fever is mild. In May and June, when yang-qi is abundant, if damaged by cold, the resulting fever is severe. In July and August, when yang-qi is declining, if damaged by cold, the resulting fever is also slight. From this, we know that for seasonal cold epidemics and warm/heat diseases, the discussion on the abundance or decline of yang-qi and the months involved is consistent. However, the cold of sudden weather differs from the cold of latent pathogens that have already transformed; they are contradictory. If names are incorrect, speech does not flow logically. Zhang Zhongjing further stated: "This disease resembles warm diseases and summerheat diseases, but the treatment differs." The key lies in distinguishing the sources among cold, heat, and warmth; only then will the distinction between using cold or hot medications be clear. (From *Shanghan Suoyan · Lun Shanghan Bian Wenre Bing*)
(1) After the Spring Equinox, when the weather turns warm, individuals suffering from high fever are afflicted with warm diseases. The *Neijing* (Classic of Internal Medicine) states: "Cold contracted in winter develops into warm diseases." It also states: "Taiyang disease (disease syndrome caused by pathogenic invasion of the Taiyang channel) presenting with fever, thirst, and aversion to cold is classified as a warm disease." This refers to latent pathogens from winter emerging with the seasonal warmth. However, the causes of emergence differ: some arise from contracting sudden cold out of season; some from irregular diet and overwork; others from sexual exertion. Since the exogenous pathogens differ, the channels through which they emerge also vary. As stated, the pulse of warm diseases circulates through various channels, and it is unknown which channel is affected; therefore, treatment should follow the specific channel symptoms. Generally, when warm diseases manifest, there is intense thirst, restlessness, hypochondriac fullness, bitter taste in the mouth, aversion to heat rather than cold, and the pulse at the Cun Kou position is stronger than at the Ren Ying position. This clearly indicates latent pathogens moving from interior to exterior, necessarily starting from the Shaoyang channel. (From *Wenbing*)
(2) Generally, there is no rationale for inducing sweating as a primary method in treating warm diseases and heat diseases. This is because the pathogens move from interior to exterior, indicating the absence of exterior syndromes. Even if symptoms clearly indicate sudden cold out of season, with aversion to cold, headache, and a floating-tight pulse, one should not rely solely on exterior-releasing medications. (From *Wenbing*)
(3) Warm diseases and heat diseases are essentially due to stagnant heat qi, so they mostly occur in the Three Yang channels. If they occur in the Three Yin channels, they are difficult to treat. If the pulse is deep-thin, faint, or empty-large and powerless, it represents a mismatch between pulse and disease, indicating certain death. However, occurrences in the Three Yin channels must have underlying causes, such as spleen injury from cold food or kidney injury from sexual activity. In these cases, healthy qi is first damaged, allowing heat toxins to erupt upon deficiency. If sweet-warm tonifying methods are used, it would only exacerbate the pathogen. If bitter-cold purgative methods are employed, vital essence (Zhenyuan) will rapidly perish. Even if Zhang Zhongjing or Liu Wansu were to return, they might find it difficult to save the patient. (From *Rebing*)