相火当乎巳午。巳为五阳。午为六阳。此太阳之正候。所以主夏令者也。而曰少阳者。其时虽六阳出地。而未极乎
上。故犹曰少阳。非以春生之少阳为少阳也。在司天则本于寅申。火长生于寅。而六阳极于申。此专以暑热从事者也。
暑热为本。少阳为标。少阳所至。为嚏呕疮疡。惊躁瞀昧。暴病。喉痹耳鸣。呕涌暴注。 螈暴死。暑热所乘。必暴速。
故其为病暴烈。亦以其为无阴也。若暑乘所胜。则与阳明胃为应。故热客于胃。烦心心痛。目赤欲呕。呕酸善饥。耳痛
溺赤。善惊谵妄。暴热销铄。少腹痛。下沃赤白。夫热客于胃。上蒸于心。故烦心心痛。少阳标在胆。起目锐 。故目
赤欲呕。呕酸者。胆亦热也。胃强故善饥。少阳脉入耳。故耳痛。阳明热浸淫水道。故溺赤。阳明当心部。又着入心。
故使心惊而语妄。暴热销铄者。溽暑使然矣。少腹痛。下沃赤白者。二肠络为阳明太阳。故俱受暑也。若相火在下而不
升。则必内乘三焦。而伤血分。民病注泄赤白。少腹痛溺赤。甚则便血者。即今所谓时行痢也。血便有痢纯血与尿血之
证。皆病在中下二焦。而内伤血分使然也。此所谓在泉也。大概热淫所胜。虽肺金受病。而胸中烦热。血干右 满。血
泄溺色变。腹大满等症。实阳明三焦病。又不止血溢鼽嚏。皮肤痛寒热喘咳等为伤肺也。惟其暴速。故其病主掉眩惊骇。
上热郁。血溢血泄心痛。而乘于土金水。则又体重 肿。痞饮病肩背胸中寒浮肿。是以病机曰。诸腹胀大。皆属于热。
诸病有声。鼓之如鼓。。皆属于热。诸转反戾。水液混浊。皆属于热。诸呕吐酸。暴注下迫。皆属于热。由是观之。诸腹
胀大。声如鼓。火乘阳明也。诸转反戾。水液混浊。火乘少阳太阳也。诸呕吐酸。奔迫下注。火乘三焦也。盖相火外发。
则丹疹丹 。疮疡喉痹。嗌肿 螈暴死。内淫则腹胀如鼓。水液混浊。诸呕吐酸。暴迫下注。皆火之奔迫。而正气不得
行也。然此等症为遇相火所临。水运所 。故有如是。若非司天非值年。而概有是证者。则又系乎内伤脏腑相乘。不可
不察也。盖腹胀有寒有热。反转戾有肝寒筋急。水液混浊。有气化不及州都。或由相火之衰。大约相火之部病。初非一
定于热。凡此诸条。岐伯特发明运气司天使然耳。可不察而蹈粗工之说乎。
相火当令于巳时和午时。巳属五阳，午属六阳。这是太阳经的正候，所以主管夏令。但称为少阳的原因，是因为此时虽然六阳之气已出于地面，但尚未极盛于上方，所以仍称为少阳，并非指春季生发之少阳。在司天之气中，本源于寅申年。火长生於寅，而六阳极盛於申。这专门以暑热为事。暑热为本，少阳为标。少阳所至，表现为喷嚏、呕吐、疮疡、惊悸躁动、神志昏蒙、突然发病、喉痹、耳鸣、呕吐涌出、急性腹泻、抽搐及突然死亡。暑热侵袭人体，必定发病急骤迅速，所以其病症暴烈，也是因为它属于无阴（纯阳）的性质。如果暑热侵犯其所胜的脏腑，则与阳明胃相应。所以热邪客于胃，出现心烦心痛、目赤欲呕、呕吐酸水、容易饥饿、耳痛、小便赤黄、易惊、胡言乱语、高热耗伤津液、少腹痛、下利赤白脓血。热邪客于胃，向上蒸腾于心，所以心烦心痛；少阳的标气在胆，起始于目锐眦，所以目赤欲呕；呕吐酸水是因为胆也热；胃气强盛故容易饥饿；少阳经脉入耳，所以耳痛；阳明热邪浸淫水道，所以小便赤黄；阳明脉当心部，又深入心，所以使人心中惊悸且言语狂妄；高热耗伤津液是溽暑所致；少腹痛、下利赤白脓血，因为大肠小肠络属阳明和太阳，所以都受暑邪影响。如果相火在下而不升，则必然内侵三焦，损伤血分。民众患病表现为急性腹泻、下利赤白脓血、少腹痛、小便赤黄，严重的甚至便血，这就是现在所谓的时行痢疾。血便中有痢疾纯血证与尿血证，都是病在中下二焦，由内伤血分所致。这就是所谓“在泉”之气。大概热邪淫盛所胜，虽然肺金受病，出现胸中烦热、血液干枯、右胁胀满、出血、小便颜色改变、腹部胀大满闷等症状，实际上是阳明和三焦的病，也不仅仅止血溢、鼻衄、喷嚏、皮肤疼痛、寒热、喘咳等伤肺的症状。正因为发病急骤迅速，所以其病主要表现为动摇眩晕、惊骇、上热郁结、出血、便血、心痛，以及乘袭脾土、肺金、肾水，则又出现身体沉重浮肿、痞满、饮停、肩背胸中寒冷浮肿。所以病机说：各种腹胀大，都属于热；各种病有声响，叩击如鼓声，都属于热；各种筋脉转侧反折拘挛，津液混浊，都属于热；各种呕吐酸水，急性腹泻里急后重，都属于热。由此看来，各种腹胀大，声音如鼓，是火邪乘袭阳明；各种筋脉转侧反折拘挛，津液混浊，是火邪乘袭少阳和太阳；各种呕吐酸水，奔迫下注，是火邪乘袭三焦。盖因相火外发，则出现丹疹、丹毒、疮疡、喉痹、咽喉肿痛、抽搐及突然死亡；内淫则出现腹胀如鼓、津液混浊、各种呕吐酸水、急性迫注下泻，这都是火邪的奔迫，而正气不得运行。然而这些症状是遇到相火所临、水运所制，所以有如此表现。如果不是司天之年或值年，而普遍出现这些证候，则又是由于内伤脏腑相互乘克所致，不可不仔细考察。大概腹胀有寒有热，反转拘挛有肝寒筋急，津液混浊有气化不及州都（膀胱），或由相火衰弱所致。大约相火所属部位的疾病，起初并不一定全是热证。以上诸条，岐伯特别阐明运气司天在泉使然罢了，可不加考察而蹈入粗工之说吗？
Ministerial Fire (Xiang Huo) governs during the Si and Wu hours. Si belongs to Five Yang, and Wu belongs to Six Yang. This is the proper manifestation of the Taiyang (Greater Yang) channel, thus governing the summer season. However, it is called Shaoyang (Lesser Yang) because although the Qi of Six Yang has emerged from the ground, it has not yet reached its extreme in the upper region; therefore, it is still referred to as Shaoyang, not referring to the Shaoyang of spring generation. In terms of Si Tian (Heavenly Stem/Earthly Branch governing the first half of the year), it originates from Yin and Shen years. Fire is born at Yin, and Six Yang reaches its extreme at Shen. This specifically deals with summer heat. Summer heat is the root, and Shaoyang is the branch. Wherever Shaoyang arrives, manifestations include sneezing, vomiting, sores and ulcers, palpitations with restlessness, mental confusion, sudden onset of disease, throat obstruction, tinnitus, projectile vomiting, acute diarrhea, convulsions, and sudden death. When attacked by summer heat, the onset must be rapid and swift; therefore, the diseases are violent and fierce, also because they belong to "Yin-less" (pure Yang) nature. If summer heat attacks what it overcomes, it corresponds to the Yangming Stomach. Thus, when heat lodges in the Stomach, symptoms include vexation, heart pain, red eyes with desire to vomit, vomiting of sour fluid, good appetite, ear pain, dark urine, susceptibility to fright, delirium, rapid consumption due to high fever, lower abdominal pain, and dysentery with red and white discharge. Heat lodging in the Stomach steams upward to the Heart, causing vexation and heart pain; the branch of Shaoyang is in the Gallbladder, originating at the outer canthus, causing red eyes and desire to vomit; vomiting sour fluid occurs because the Gallbladder is also hot; strong Stomach Qi leads to good appetite; the Shaoyang meridian enters the ear, causing ear pain; Yangming heat infiltrates the water passages, causing dark urine; the Yangming meridian passes through the heart region and further enters the Heart, causing heart palpitations and delirious speech; rapid consumption due to high fever is caused by humid heat; lower abdominal pain and dysentery with red and white discharge occur because the Large and Small Intestines connect to Yangming and Taiyang, thus both are affected by summer heat. If Ministerial Fire remains below and does not ascend, it will internally invade the Sanjiao (Triple Burner) and damage the Blood aspect. The people suffer from acute diarrhea with red and white discharge, lower abdominal pain, dark urine, and in severe cases, hematochezia. This is what is currently known as epidemic dysentery. Conditions such as pure blood in stool (dysentery type) and hematuria all involve the Middle and Lower Jiao, resulting from internal injury to the Blood aspect. This is referred to as "Zai Quan" (Earthly Branch governing the second half of the year). Generally, when excessive Heat invades what it overcomes, although the Lung Metal suffers, presenting with vexation and heat in the chest, dried blood, distension on the right side, bleeding, changes in urine color, and abdominal distension, these are actually diseases of Yangming and Sanjiao, not merely stopping nasal bleeding, sneezing, skin pain, chills and fever, wheezing, and coughing which injure the Lung. Precisely because the onset is rapid and swift, the diseases mainly manifest as tremors, vertigo, and fright. Upper heat stagnation, bleeding, hematochezia, and heart pain occur; when it overacts on Earth, Metal, and Water, it results in heavy body and edema, fullness, fluid retention, coldness in the shoulder, back, and chest, and edema. Therefore, the Pathogenesis states: All abdominal distensions and enlargements belong to Heat; all diseases with sounds, where percussion yields a drum-like sound, belong to Heat; all tendon contractions and spasms, with turbid body fluids, belong to Heat; all vomiting and sour regurgitation, acute diarrhea with tenesmus, belong to Heat. From this perspective, abdominal distensions with drum-like sounds indicate Fire overacting on Yangming; tendon contractions and spasms with turbid fluids indicate Fire overacting on Shaoyang and Taiyang; vomiting, sour regurgitation, and urgent downward flow indicate Fire overacting on Sanjiao. When Ministerial Fire issues outward, it causes erysipelas, carbuncles, sores and ulcers, throat obstruction, pharyngeal swelling, convulsions, and sudden death; when it invades inward, it causes abdominal distension like a drum, turbid fluids, vomiting, sour regurgitation, and acute urgent diarrhea. These are all due to the rushing of Fire, while the Righteous Qi cannot circulate. However, these symptoms occur when encountering the arrival of Ministerial Fire and the restriction of Water運 (Water Cycle). If these syndromes appear generally without being in a Si Tian or Zhi Nian year, then it is due to internal injury and mutual overacting of Zang-Fu organs, which must be carefully examined. Generally, abdominal distension can be Cold or Heat; tendon contractions can be due to Liver Cold and tendon tension; turbid fluids can be due to Qi transformation failing to reach Zhou Du (Bladder), or caused by the decline of Ministerial Fire. Approximately, diseases in the domain of Ministerial Fire are not necessarily always Heat. These points were specially elucidated by Qibo regarding the influence of Si Tian and Zai Quan in Yunqi (Five Movements and Six Qi); one should not fail to examine them and fall into the errors of incompetent physicians.