Source 出处 · Wenbing Tiaobian · Doses are not given here: they are set by a licensed practitioner for the individual.
Safety. Wu Jutong's Wenbing Tiaobian is the mature statement of the warmth disease tradition, and this is among its most-quoted formulas. Its indication is a shape rather than a list of symptoms: fever that arrives at night and has cleared by morning, and - the detail that carries the diagnosis - fever that settles without sweating. That last clause is the hinge, because a fever that breaks with sweat is read as a different situation altogether. Here the heat is understood to lie too deep for surface-releasing methods to reach and too entrenched for simple clearing, so the formula nourishes the yin that is being consumed while a light aromatic herb draws the residual heat outward to where it can leave. It is a genuinely elegant construction and it reads well. Whether any of it corresponds to an identifiable modern entity is not something this entry can settle, and saying so is better than implying otherwise.
Four things then follow, and the first two matter more than the pattern.
One. This formula contains qing hao, and qing hao is where artemisinin comes from. Those two facts invite a conclusion that is false and dangerous. Artemisinin was isolated from Artemisia annua by Chinese researchers in the 1970s, work for which Tu Youyou received the 2015 Nobel Prize, and the line that steered it - take a handful of qing hao, soak it in two sheng of water, wring out the juice and drink all of it - comes from Ge Hong's Zhouhou Beiji Fang. That sentence describes a cold preparation rather than a decoction, which is precisely why the modern isolation worked. Artemisinin today is given as artemisinin-based combination therapy with a partner drug, and that combination and schedule exist specifically to prevent resistance. This formula is not that. It is not an antimalarial in this sense, its composition and preparation belong to a different purpose, and treating malaria with it would mean treating a life-threatening parasitic disease with the wrong thing. The World Health Organization has advised against Artemisia infusions and teas for malaria, on the grounds that the amount of artemisinin they deliver is unpredictable and that sub-therapeutic exposure encourages resistance. That warning attaches to the herb on its own, and it bears with more force on a five-ingredient decoction.
Two. The name is also a botany problem worth knowing. In modern Chinese materia medica qing hao is Artemisia annua - but Artemisia annua is the plant that classical botany calls huang hua hao, while the plant identified as qing hao in older sources is generally taken to be a different species. The Chinese Pharmacopoeia resolved the mismatch in favour of the modern usage. So the classical record and the modern dispensary label may not point at the same plant, and this is one of the better-documented cases of that divergence. Either way it is Asteraceae, which is a genuinely allergenic family - the same family that makes mugwort and ragweed pollens a problem.
Three. Bie jia is turtle plastron. The Chinese softshell turtle, Pelodiscus sinensis, is listed in CITES Appendix II and assessed as Vulnerable by the IUCN, so trade in it is regulated. It is also farmed on an enormous scale for food, and farmed material overwhelmingly supplies the materia medica market, so the practical answer to most sourcing questions is a farm rather than the wild - but the question is legitimate and this entry will not pretend otherwise. It is also not a vegetarian product, and no one should meet it unannounced.
Four. Fever at night and cool by morning has a modern differential that includes tuberculosis, lymphoma, endocarditis, brucellosis, HIV and malaria among others, and tuberculosis is the one that matters most here. It is contagious, it needs months of specific antimicrobial therapy, and night fever with drenching sweats is how it classically presents. Persistent unexplained fever is investigated before it is patterned.
吴鞠通《温病条辨》是温病学派成熟形态的表述，而此方是书中被引用最多的一首。它的主治不是一个症状清单，而是一个形状：夜热早凉，以及——承载诊断的那一点——热退而无汗。最后这一句是枢纽，因为汗出热退在书中被读作另一种情形。这里的热被认为是伏得太深，解表之法够不着，又胶固到单纯清热难以拔除，于是此方一边补益正在被消耗的阴，一边用一味轻清芳香之品把残余的热引到表浅处让它有路可退。这是一个确实精巧的结构，读起来也漂亮。至于它是否对应任何可以被现代归类的实体，本条无法裁决，而承认这一点比暗示相反要好。
接着有四件事，而前两件比那个证候更要紧。
其一：此方含青蒿，而青蒿正是青蒿素的来源。这两个事实会诱出一个错误而危险的结论。青蒿素是中国研究者在二十世纪七十年代从黄花蒿中分离出来的，屠呦呦因此获得 2015 年诺贝尔奖；而指引这项工作的那句话——「青蒿一握，以水二升渍，绞取汁，尽服之」——出自葛洪《肘后备急方》。这句话描述的是冷浸取汁而非水煎，这正是现代分离能够成功的原因。今天青蒿素以青蒿素类复方给药，配伍另一种药物，而这个组合与时程的存在本身就是为了防止耐药。此方不是那个东西。它不是这个意义上的抗疟方，它的组成与制法属于另一个目的，用它来对付疟疾，等于用错的东西去处理一种危及生命的寄生虫病。世界卫生组织也已建议不要用青蒿的浸剂或茶饮来治疗疟疾，理由是它们能提供的青蒿素量不可预测，而低于治疗水平的暴露会助长耐药。这一警告针对的是单味草药本身，而它施加于一首五味药的汤剂时只会更有分量。
其二：这个名字本身也是一个值得知道的植物学问题。在现代中药学里，青蒿是黄花蒿 Artemisia annua；但 Artemisia annua 恰恰是古典植物学称作「黄花蒿」的那种植物，而旧籍中被认作「青蒿」的一般被认为是另一种。《中国药典》的选择是把这个错位按现代用法了结。因此古典记载与现代调剂标签未必指向同一株植物，而这正是此类错位里记载得较好的例子之一。无论如何它属菊科，而菊科是确实容易致敏的一科——让艾蒿与豚草花粉成为问题的正是这一科。
其三：鳖甲是鳖的腹甲。中华鳖 Pelodiscus sinensis 被列入 CITES 附录二，并被国际自然保护联盟评估为易危，故其贸易受管制。它同时以极大的规模养殖供食用，而药材市场供应的绝大多数来自养殖，所以对大多数来源问题而言实际的答案是养殖场而非野外——但这个问题是正当的，本条不会装作它不存在。它也不是素食者可用的东西，不应有人意外地遇到它。
其四：「夜热早凉」在现代有一个鉴别目录，其中包括结核、淋巴瘤、心内膜炎、布鲁氏菌病、HIV 感染与疟疾等，而这里最要紧的是结核。它传染，需要数月的针对性抗微生物治疗，而夜间发热伴大汗正是它的典型起病方式。持续不明原因的发热，应当先查，再谈辨证。