麻疹非热不出，然有微热，有壮热，有乍热潮热复热之不同。微热者热轻而不壮，惟
初起为宜。正出之时，热不可微，微则不能透表，将没及没后见此，为疹毒已尽，不须
服药。壮热者经日不退，正出时是为正候。若初起壮热，直至已出不少减，其症必重。没
时壮热不退，尤为不宜，急当用药清解，热退神安，方可无虑。然亦有没后壮热，口干
唇燥，昏睡沉沉，服清凉解毒之药，热退身冷如冰，少时又复大热，再投以芩、连之类，
全无应效。而且面色青惨，喉作鸡声，头摇目泛，气喘神昏，此为中气虚寒，浮阳外越，
有不得终日之势。非大辛大热之品，不足以冲开寒痰反真阳于内府，速用熟附汤，或加
肉桂、胡椒、炮姜之类，接用附子理中汤，合六味丸料，去泽泻、丹皮，加枸杞子、破故
纸，庶使寒消阳复，风熄痰平，再加枣仁、白芍、五味子，以敛其阴，所谓甘温能除大热，
正此意也。有热数日止，过数日又热，或一日间早热午凉，中热暮止，均为乍热，未出
时见之，毒邪难透，宜疏散，正出时见之，恐毒攻内，宜疏托。若没后乍热，毒邪未尽，当
凉解分利。又有一日一度，如潮水之信，来不失期曰潮热。初时必无此症，出尽及没后，
气血两虚，营卫之行，失其常度，故热应时而作，宜益阴退阳，乃为正治。复热者热已
退而复发，亦没后有之，是余毒未尽，治宜凉解总之疹子出透，其热当减。倘仍大热者，
宜化毒清表汤，疹已收没而身热者，宜柴胡清热饮。
麻疹并非没有热象就不能发出，然而发热有轻微发热、高热，以及忽冷忽热、潮热和复发的不同情况。轻微发热是指热度较轻而不剧烈，这仅在发病初期是适宜的。在疹子正当透发的时候，发热不可轻微，如果太轻微则不能将毒邪透出体表；如果在疹子将要消退及消退后出现这种微热，说明疹毒已经排尽，不需要服药。高热是指持续多日不退，在疹子正当透发时出现属于正常征候。如果在发病初期就高热，直到疹子发出不少也没有减退，病情必然严重。在疹子消退时高热仍不退，尤其不适宜，应当紧急用药清热解表，待热退神志安宁，才可以没有顾虑。然而也有在疹子消退后出现高热的，表现为口干唇燥，昏沉嗜睡，服用清凉解毒的药物后，热退但身体冷如冰，过了一会儿又再次大热，再投以黄芩、黄连之类的药物，完全没有效果。而且面色青惨，喉间发出鸡鸣样的声音，头摇目眩，气喘神昏，这是中气虚寒，浮阳外越，有性命之忧的危重态势。非用大辛大热的药物，不足以冲开寒痰，引真阳回归内腑，应迅速使用熟附汤，或者加入肉桂、胡椒、炮姜之类，接着使用附子理中汤，配合六味丸的药料，去掉泽泻、丹皮，加入枸杞子、补骨脂，使得寒气消散阳气恢复，风熄痰平，再加酸枣仁、白芍、五味子，来收敛阴液，这就是所谓的“甘温能除大热”，正是这个意思。有的发热几天停止，过了几天又发热，或者一天之中早晨发热中午凉爽，中午发热傍晚停止，都称为乍热（忽冷忽热）。在未出疹时见到，是因为毒邪难以透出，宜用疏散法；在正当透发时见到，恐怕毒邪攻入内脏，宜用疏托法。如果在疹子消退后出现乍热，说明毒邪未尽，应当用清凉解表和分利小便的方法治疗。还有一种是一天发作一次，像潮水一样准时，来去不失期，称为潮热。初起时一定不会有这种症状，在疹子出尽及消退后，因为气血两虚，营卫的运行失去常态，所以发热按时发作，宜用益阴退阳的方法，这才是正治法。复发热是指热已退去而又重新发热，也是在疹子消退后出现的，这是因为余毒未尽，治疗宜用清凉解表法。总之，疹子出透之后，其发热应当减轻。如果仍然大热的，宜用化毒清表汤；疹子已经收没而身体仍有发热的，宜用柴胡清热饮。
Measles cannot erupt without heat; however, there are differences in mild fever, high fever, and alternating fevers, tidal fevers, and recurrent fevers. Mild fever refers to a slight heat that is not intense, which is only appropriate at the initial stage of onset. During the proper eruption phase, the fever should not be mild; if it is too mild, the pathogenic factors cannot be vented through the exterior. If such mild fever appears when the rash is about to subside or after it has subsided, it indicates that the measles toxin has been completely exhausted, and no medication is required. High fever refers to persistent heat lasting several days; appearing during the proper eruption phase is considered a normal sign. If high fever occurs at the onset and does not decrease significantly even after the rash has erupted, the condition must be severe. It is particularly inadvisable for high fever to persist during the subsidence phase; urgent treatment with clearing and resolving medications is needed. Only when the fever subsides and the spirit becomes calm can one be free from worry. However, there are cases of high fever after subsidence, characterized by dry mouth and lips, deep lethargy, and drowsiness. After administering cooling and detoxifying herbs, the fever may subside but the body becomes cold as ice, followed by a return of high fever shortly thereafter. Administering herbs like Huangqin (Scutellariae Radix) and Lianzi (Coptidis Rhizoma) yields no effect. Furthermore, the complexion is dark and grim, the throat makes a sound like a crowing chicken, the head shakes, the eyes are unfocused, accompanied by panting and coma. This indicates deficiency-cold of the Middle Jiao (the digestive system's functional center) and floating Yang escaping outward, a critical condition threatening life within a day. Only potent acrid-hot substances can break open cold-phlegm and guide True Yang back to the internal organs. One should immediately use Shu Fu Tang (Prepared Aconite Decoction), or add Rougui (Cinnamon Bark), Hujiao (Pepper), and Paojiang (Baked Ginger). Subsequently, use Fuzi Lizhong Tang (Aconite Decoction to Regulate the Middle) combined with the ingredients of Liuwei Wan (Six-Ingredient Pill with Rehmannia), removing Zexie (Alisma Rhizome) and Danpi (Moutan Cortex), and adding Gouqizi (Lycium Fruit) and Poguzhi (Psoralea Fructus). This aims to dissipate cold, restore Yang, extinguish wind, and resolve phlegm. Additionally, add Zaoren (Ziziphus Seed), Baishao (White Peony Root), and Wuweizi (Schisandra Fruit) to astringe Yin. This embodies the principle that "sweet-warm [herbs] can eliminate great heat." Some patients experience fever that stops for a few days and returns after several days, or fever in the morning, coolness at noon, fever at midday, and cessation at dusk. These are all classified as alternating fevers. When seen before eruption, it indicates difficulty in venting the toxin, requiring dispersing methods. When seen during eruption, it suggests fear of the toxin attacking inward, requiring dispersing and supporting methods. If alternating fever occurs after subsidence, it indicates incomplete exhaustion of the toxin, requiring cooling, resolving, and diaphoretic-diuretic methods. Another type occurs once daily, regular as the tide, known as tidal fever. This symptom is absent initially; it appears after the rash has fully erupted and subsided due to dual deficiency of Qi and Blood, causing the circulation of Ying (Nutritive Qi) and Wei (Defensive Qi) to lose its normal rhythm, resulting in timed fever. The correct treatment is nourishing Yin and retreating Yang. Recurrent fever refers to fever returning after having subsided, also occurring after subsidence, indicating residual toxin; treatment requires cooling and resolving methods. In summary, once the measles have fully erupted, the fever should diminish. If high fever persists, Huadu Qingbiao Tang (Toxin-Resolving Exterior-Clearing Decoction) is indicated. If fever remains after the rash has receded and subsided, Chaihu Qingre Yin (Bupleurum Heat-Clearing Decoction) is indicated.