昔人云∶变者易也生五脏，蒸者热也养六腑，轻则发热似惊，重则壮热烦躁，三十二日一变，六十四日
一蒸，至五百七十六日变蒸即毕，儿乃成人也。其说似以为小儿自幼而长，必经变蒸，故有发热似惊，
壮热烦躁之象并非病象，而属于自然之现象，此未可尽信者也。考小儿平时保护得宜，至长无病，惟当出
牙之时，则常有自然之发热，出牙一次，发热一次，牙出之后，其热自退，此殆变蒸之说之由来也。又人
身本有抵抗疾病之能力，小儿亦然，往往小儿因起居不慎，饮食不节，感染小恙，随
即发热，其后因自身抵抗之力，而将疾病消灭于无形，故小儿常有似病非病之象，不久即霍然而愈者，
此殆变蒸之又一说也。准此则变蒸之治法，宜就以上之情状而为相当之治疗，决不可漫不注
意而贻小儿以后患也。
一、出牙发热之治法
小儿第四个月至第十个月内，齿牙渐次出生，最初出生之二齿，为下牙床之门齿，继则出生上牙床之门
齿一对，若上牙床门齿先出，或先出一枚者，皆为不良之现象。其出生之迟早，亦因
人而异，早则四五月出生，迟则至十月方出，亦有落地时已有牙者，亦有一周岁方出牙者，则百人中偶有一
二也。至于出牙之时，最普通之征象，常为身体发热，胃口不良，甚则睡眠不安，
时时惊惕，或兼有泄泻，或兼有呕吐，此时可验其牙床微胀或作浮肿，渐露白色齿头者，即出牙证也。牙齿
顶穿牙床而露头之时，因生长之力较速，故现发热之状，发热虽非病征，然引起他
种之病恙，则不得根据法治之。譬如因发热则消化为之迟钝，胃中失其常序，而呕吐之证见矣，肠中失其常
序而泄泻之证见矣，皆宜酌用清凉退热及辅助消化之剂。体实者多佐以退热、消痰、清
火之药，体虚者多佐以健脾、扶气、化积之药，虽见证治证，与一般疾病之治相同，然切忌过于苦寒克伐
香窜之品，以暗耗其生长之气，此于出牙时之所宜注意者也。
二、感冒发热之治法
小儿无端发热，若不因于内伤者，非属感寒，即属伤风，非属受湿，即属受热，均宜按证治之。
发热无汗者宜微汗之，发热有汗者宜和之，热轻者轻清解表，热重者清凉退热，因寒因风因
湿因热，俱于成法之中，酌为变通，用其小剂，盖小儿脏腑娇嫩，不耐过剂之药，若投药中病，则体力恢复
甚易，轻微小恙，自必退除，所谓平淡有奇功，于此恒最适用也。
古人说：变，就是改变，指生成五脏；蒸，就是发热，指滋养六腑。轻的表现为低热类似惊风，重的表现为高热烦躁。每三十二天发生一次“变”，每六十四天发生一次“蒸”，直到五百七十六天时，“变蒸”过程结束，孩子才算是真正长大成人。这种说法似乎认为，小儿从幼年到成长，必须经历“变蒸”的过程，因此出现的低热似惊、高热烦躁等现象并非病态，而是属于自然现象，这一点是不可完全相信的。考察发现，如果小儿平时护理得当，生长发育过程中没有生病，只有在出牙的时候，常常会有自然的发热，每出一颗牙就发热一次，牙齿长出后，热度自然消退，这大概是“变蒸”学说的由来。另外，人体本身具有抵抗疾病的能力，小儿也是如此。往往因为小儿起居不慎、饮食不节，感染了轻微的小病，随即出现发热，之后因为自身抵抗力的作用，将疾病在无形中消灭掉，所以小儿常有看似生病其实没病的状况，不久后就突然痊愈了，这大概是“变蒸”学说的另一种解释。根据上述情况，“变蒸”的治疗应当根据以上的情状进行相应的治疗，决不可以漫不经心而给小儿留下后患。
一、出牙发热的治法
小儿在第四个月到第十个月期间，牙齿逐渐长出。最初长出的两颗牙齿是下牙床的门牙，接着长出上牙床的一对门牙。如果上牙床的门牙先长出来，或者只长出一颗，都是不良的现象。牙齿长出的迟早因人而异，早的在四五个月时长出，迟的要到十个月才出，也有出生时就有牙齿的，或者要到一周岁才长牙的，这种情况一百人中偶尔有一两个。至于出牙时，最普通的征象通常是身体发热、胃口不好，甚至睡眠不安、时时惊惕，或者兼有腹泻，或者兼有呕吐。此时可以检查其牙床微胀或浮肿，渐渐露出白色齿头，这就是出牙证。牙齿顶穿牙床露头之时，由于生长速度较快，所以出现发热的状况。发热虽然不是病征，但如果引起了其他病症，就不能按照常规方法治疗。例如因为发热导致消化变得迟钝，胃中失去正常秩序，从而出现呕吐的症状；肠中失去正常秩序，从而出现腹泻的症状，这些都应当酌情使用清凉退热及辅助消化的药剂。体质强壮的多配合使用退热、消痰、清火的药物，体质虚弱的多配合使用健脾、扶气、化积的药物。虽然见证施治与一般疾病的治法相同，但切忌过度使用苦寒克伐、香窜耗散的药物，以免暗中消耗其生长的元气，这是出牙时所应该注意的。
二、感冒发热的治法
小儿无故发热，如果不是因为内伤引起的，要么是感受寒邪，要么是伤风，要么是受湿，要么是受热，都应当根据症状进行治疗。发热无汗的宜用微汗法，发热有汗的宜用和解法，热轻的用轻清解表法，热重的用清凉退热法。无论是因寒、因风、因湿还是因热，都在成法之中，酌情变通，使用小剂量药方。这是因为小儿脏腑娇嫩，不能耐受过量药物，如果用药对症，体力恢复很容易，轻微的病痛自然会消除，所谓平淡之药有奇效，在此处最为适用。
Ancient texts state: "Bian" (Change) refers to the transformation and generation of the Five Zang Organs; "Zheng" (Steaming/Heat) refers to the warming and nourishment of the Six Fu Organs. In mild cases, it manifests as low-grade fever resembling convulsions; in severe cases, it presents as high fever with irritability. A "Bian" occurs every 32 days, and a "Zheng" occurs every 64 days. This process concludes at 576 days, after which the child is considered fully grown. This theory seems to imply that children must undergo "Bian Zheng" from infancy to adulthood, and thus symptoms like low-grade fever resembling convulsions or high fever with irritability are not pathological but natural phenomena. However, this view cannot be entirely accepted. Upon examination, if a child is properly cared for and grows up without illness, natural fever typically occurs only during teething. Each episode of teething is accompanied by fever, which subsides naturally once the teeth erupt. This is likely the origin of the "Bian Zheng" theory. Furthermore, the human body possesses innate resistance to disease, and children are no exception. Often, due to improper living habits or irregular diet, a child may contract a minor ailment and subsequently develop a fever. Later, through their own immune resistance, the disease is eliminated invisibly. Thus, children often exhibit symptoms that appear ill but are not truly diseased, recovering suddenly shortly thereafter. This constitutes another explanation for the "Bian Zheng" theory. Based on these observations, the treatment for "Bian Zheng" should be adapted to these specific conditions. One must never neglect these signs, lest they cause future harm to the child.
1. Treatment for Teething Fever
Between the fourth and tenth months of age, a child's teeth gradually erupt. The first two teeth to emerge are usually the lower central incisors, followed by the pair of upper central incisors. If the upper central incisors erupt first, or if only one emerges, it is considered an abnormal phenomenon. The timing of eruption varies among individuals; some erupt teeth at four or five months, while others do not until ten months. Rarely, a child may be born with teeth, or may not erupt teeth until one year of age (occurring in one or two out of every hundred cases). The most common signs during teething include body fever, poor appetite, restlessness during sleep, frequent startles, and potentially diarrhea or vomiting. At this time, one can observe slight swelling or edema of the gums, with white tooth tips gradually appearing, confirming the diagnosis of teething. When the teeth pierce the gum tissue, the rapid growth force causes a febrile state. Although fever itself is not a pathological sign, if it induces other ailments, standard treatments must not be applied rigidly. For instance, fever may slow digestion and disrupt gastric order, leading to vomiting; it may also disrupt intestinal order, leading to diarrhea. In such cases, appropriate cooling, antipyretic, and digestive-aiding preparations should be used. For children with strong constitutions, herbs for clearing heat, resolving phlegm, and purging fire are added; for those with weak constitutions, herbs for strengthening the Spleen, supporting Qi, and resolving stagnation are added. While the symptomatic treatment resembles that of general diseases, one must strictly avoid excessive use of bitter-cold, draining, or acrid-aromatic drugs, which could secretly deplete the child's vital growing energy. This is a crucial point to note during teething.
2. Treatment for Cold-Induced Fever
If a child develops unexplained fever not caused by internal injury, it is either due to cold invasion, wind damage, dampness accumulation, or heat accumulation. Treatment should be tailored to the specific syndrome. For fever with no sweating, a mild diaphoretic method is indicated; for fever with sweating, harmonization is indicated. For mild heat, light and clear exterior-resolving methods are used; for severe heat, cooling and antipyretic methods are employed. Whether the cause is cold, wind, dampness, or heat, modifications should be made within established protocols, using small dosages. This is because children's Zang-Fu organs are delicate and cannot tolerate heavy medication. If the medication targets the pathology correctly, physical strength recovers easily, and minor ailments will naturally subside. The principle that "bland remedies yield miraculous results" is most applicable here.