帝曰∶夫病温疟与寒疟，而皆安舍？舍于何脏？岐
伯曰∶温疟得之冬中于风寒，气藏于骨髓之中，至春则阳气大发，邪气不能自出，因遇大暑，脑髓烁，肌肉消，
腠理发泄，或有所用力，邪气与汗皆出。此病藏于肾，其气先从内出之于外也。如是者，阴虚而阳盛，阳盛则
热矣，衰则气复反入，入则阳虚，阳虚则寒矣，故先热而后寒，名曰温疟。
《生气通天论》、《阴阳应象大论》皆曰∶冬伤于寒，春必温病，是伏邪发于少阴经络也。故仲景论伏气
温病，必先喉痛，以少阴经脉循喉系舌本故也，然肾司冬令而主骨，此其邪入深，而云藏于骨髓，故至春阳气
虽大发，而邪气不能自出，因又遇大暑，其邪久伏，郁极而成热，烁髓消肌，腠理发泄，或有所用力以动阳，
其邪始与汗皆出。此因先藏于肾，从内出外，故其阴已虚，而阳邪盛，阳盛则热矣；盛极必衰，衰则邪气复反
入阴，入阴则阴盛阳虚，阳虚则寒矣。故先热而后寒，以其邪本温热，因入于阴而身寒，故名温疟，非寒邪也。
其寒疟之由，已详上文矣。
帝曰∶瘅疟何如？岐伯曰∶瘅疟者，肺素有热，气盛于身，厥逆上冲，中气实而不外泄，因有所用力，腠
理开，风寒舍于皮肤之内、分肉之间而发，发则阳气盛，阳气盛而不衰，则病矣。其气不及于阴，故但热而
不寒，气内藏于心，而外舍于分肉之间，令人消烁肌肉，故命曰瘅疟。
肺素有热者，以其阳盛于身也，阳盛则升气多而厥逆上冲，
中气实而不外泄，所以肺热也。因有所用力而腠理开，风寒乘虚客于皮肤分肉之间，以其阳盛，邪即化热，
心为君火，同气相召，故藏于心，而外舍于分肉之间，则消烁肌肉。其邪不及于阴，故但热而不寒，命曰瘅疟
也。大抵疟之发寒热者，以邪气出入阴阳，阴阳之气互争互并故也。然邪必随身中之气变化，故阳盛之人，邪
即化热，阳虚之人，邪易入阴，入阴则阴盛多寒，客阳则阳盛多热。瘅疟之邪，不及于阴，故但热而不寒也。
又有湿闭热伏之病，亦由阳气不振，或见其内热而投寒药，则湿邪愈闭而阳陷，乃至危殆矣。此阴阳强弱，
邪之浅深，不可不辨也。
黄帝问道：温疟和寒疟这两种病，病邪都藏在哪里？具体藏在哪个脏腑？
岐伯回答说：温疟是由于冬季感受了风寒之邪，邪气潜伏在骨髓之中。到了春季，阳气大发，但邪气不能自行排出；如果又遇到大暑天气，脑髓被灼热，肌肉消瘦，腠理（皮肤毛孔）开泄，或者因为用力劳作，邪气就随着汗液一起排出体外。这种病的病位藏在肾，其气机先从体内向外发散。像这种情况，属于阴虚而阳盛，阳盛就会产生热象；当阳气衰退时，气机又会反向内入，内入则导致阳虚，阳虚就会产生寒象。所以表现为先发热而后发冷，命名为温疟。
《生气通天论》和《阴阳应象大论》都说：“冬季受寒邪伤害，春天必定发生温病”，这是伏邪发于少阴经络的缘故。所以张仲景论述伏气温病时，必然伴有咽喉疼痛，因为少阴经脉循行经过喉咙并联系舌根。然而，肾主管冬季的时令且主司骨骼，邪气深入，所以说它藏在骨髓中。因此，到了春季虽然阳气大发，但邪气不能自行排出，如果又遇到大暑，邪气久伏体内，郁积至极点而化热，灼烧脑髓、消耗肌肉，腠理开泄，或者因用力劳作以调动阳气，邪气才随汗液一同排出。这是因为邪气先藏在肾，从内向外发散，所以阴气已经虚弱，而阳邪亢盛，阳盛则产生热象；亢盛到极点必然衰退，衰退时邪气又重新陷入阴分，陷入阴分则阴气盛而阳气虚，阳气虚则产生寒象。所以先发热而后发冷，因为邪气本质是温热，因进入阴分而导致身体发冷，所以命名为温疟，并非寒邪所致。至于寒疟的成因，已在上面详细论述过了。
黄帝问道：瘅疟（dān nüè，一种但热不寒的疟疾）是什么样的？
岐伯回答说：瘅疟患者，肺中素有热邪，体内气机亢盛，气逆向上冲撞，中焦之气充实而不能向外宣泄。如果因为用力劳作，腠理开泄，风寒之邪便停留在皮肤之内、分肉之间而发病。发病时阳气亢盛，如果阳气亢盛而不衰退，就会生病。邪气不及于阴分，所以只发热而不发冷。邪气内藏于心，外舍于分肉之间，使人肌肉消烁，所以命名为瘅疟。
所谓“肺素有热”，是因为阳气在体内亢盛。阳气亢盛则升发之气多且气逆上冲，中焦之气充实而不能外泄，这就是肺热的表现。因为用力劳作导致腠理开泄，风寒乘虚侵入皮肤和分肉之间。由于患者阳气亢盛，邪气随即化为热邪。心为君火，与热邪同气相求，所以邪气藏于心，外舍于分肉之间，从而消烁肌肉。因为邪气不及于阴分，所以只发热而不发冷，命名为瘅疟。
大抵来说，疟疾发作时出现寒热往来，是因为邪气出入于阴阳之间，阴阳二气相互争斗、交并的缘故。然而，邪气必然会随着人体内部的气机变化而变化。所以，阳气亢盛的人，邪气即化为热邪；阳气虚弱的人，邪气容易陷入阴分，陷入阴分则阴气盛而多寒，客居阳气则阳气盛而多热。瘅疟的邪气不及于阴分，所以只发热而不发冷。
另外，还有湿邪闭阻、热邪潜伏的病证，也是由于阳气不振，或者见到内热症状就投用寒凉药物，导致湿邪更加闭阻而阳气下陷，甚至达到危险境地。这其中的阴阳强弱、邪气的浅深，是不可不辨别的。
Yellow Emperor asked: Where do the pathogens of Warm Malaria (Wen Nue) and Cold Malaria (Han Nue) reside? In which Zang organs are they stored?
Qi Bo replied: Warm Malaria arises from contracting Wind-Cold in winter. The pathogen hides within the Marrow (Gu Sui). When spring arrives, Yang Qi expands vigorously, but the pathogen cannot expel itself. If accompanied by intense summer heat, the brain marrow is scorched, muscles waste away, and Cou Li (pores/skin texture) open and sweat. Or, if physical exertion occurs, the pathogen exits along with the sweat. This disease resides in the Kidney (Shen), and its Qi moves from the interior to the exterior. In such cases, Yin is deficient while Yang is excessive; Yang excess generates Heat. When Yang declines, the Qi reverses and re-enters the interior; interior entry leads to Yang deficiency, and Yang deficiency generates Cold. Thus, it presents with fever first followed by chills, named Warm Malaria (Wen Nue).
Both *Su Wen: Lun Sheng Qi Tong Tian* and *Yin Yang Ying Xiang Da Lun* state: "Injury by Cold in winter leads to Warm Diseases in spring." This indicates that latent pathogens emerge from the Shaoyin (Lesser Yin) meridians. Therefore, Zhang Zhongjing discusses latent Qi Warm Diseases as necessarily involving sore throat, because the Shaoyin meridian circulates through the throat and connects to the root of the tongue. However, the Kidney governs the Winter season and controls the bones. Since the pathogen enters deeply, it is said to hide in the bone marrow. Thus, even though Yang Qi expands greatly in spring, the pathogen cannot exit spontaneously. If intense summer heat follows, the long-latent pathogen becomes stagnant and transforms into Heat, scorching marrow and wasting muscles. With Cou Li opening or physical exertion mobilizing Yang, the pathogen finally exits with sweat. Because the pathogen initially resided in the Kidney and moved from interior to exterior, Yin is already deficient while Yang pathogens are excessive; Yang excess generates Heat. Excess inevitably declines; upon decline, the pathogen re-enters Yin. Entry into Yin causes Yin excess and Yang deficiency; Yang deficiency generates Cold. Hence, fever precedes chills. Because the pathogen is essentially warm-hot, but causes coldness upon entering Yin, it is named Warm Malaria (Wen Nue), not caused by Cold pathogens. The cause of Cold Malaria (Han Nue) has been detailed above.
Yellow Emperor asked: What is about Damp-Heat Malaria (Dan Nue)?
Qi Bo replied: In Dan Nue, the Lungs (Fei) harbor pre-existing Heat, causing Qi to be excessive throughout the body. Rebellious Qi rushes upward, Middle Qi is full but fails to vent outward. If physical exertion opens the Cou Li, Wind-Cold lodges between the skin and muscle layers (Fen Rou), triggering the disease. Upon onset, Yang Qi becomes excessive; if this excess does not subside, illness persists. The pathogen does not reach the Yin level, so there is only fever without chills. The Qi stores internally in the Heart (Xin) and externally in the Fen Rou, causing muscle wasting; thus it is named Dan Nue.
"Pre-existing Heat in the Lungs" implies excessive Yang in the body. Yang excess leads to abundant ascending Qi and rebellious upward rushing, with full Middle Qi failing to vent, resulting in Lung Heat. Physical exertion opens Cou Li, allowing Wind-Cold to invade the skin and Fen Rou due to deficiency. Due to excessive Yang, the pathogen immediately transforms into Heat. The Heart is the Sovereign Fire; sharing similar nature, it attracts the pathogen. Thus, the pathogen stores in the Heart and lodges in the Fen Rou, wasting muscles. Since the pathogen does not reach Yin, there is only fever without chills, named Dan Nue.
Generally, malaria presenting with alternating chills and fever occurs because pathogens move between Yin and Yang, causing mutual contention and merging of Yin and Yang Qi. However, pathogens change according to the body's internal Qi. Thus, in those with Yang excess, pathogens transform into Heat; in those with Yang deficiency, pathogens easily enter Yin. Entering Yin causes Yin excess and much Cold; lodging in Yang causes Yang excess and much Heat. Dan Nue pathogens do not reach Yin, hence only fever without chills.
Furthermore, diseases of Dampness obstruction and latent Heat also arise from failing Yang Qi. If one sees internal Heat and administers Cold herbs, Dampness becomes more obstructed and Yang sinks, leading to critical danger. The strength of Yin and Yang, and the depth of pathogens, must be distinguished carefully.