夫伤寒传染之由者，因闻大汗秽毒，以致神狂气乱，邪热暴甚于内，作发于外而为病也。则如西山记曰∶
近秽气而触真气。钱仲阳云∶步履粪秽之履，无使近于婴儿，若闻其气，则令儿急惊风搐也。孙真人云∶
乘马远行，至暮当沐浴、更衣，然后方可近于婴儿，使不闻马汗气毒，不然则多为天吊、急惊风搐也。故
剥死马者，感其毒瓦斯而成马气、丁黄之疾，皆由闻其毒瓦斯之所作也。故《圣惠方》
一法，大汗出则悬药于户，辟其大汗秽毒，无使伤于人也。世以艾灸席隅者，皆
其义也。多染亲属，忧戚侍奉之人，劳役者，由其神气怯弱，易为变乱故也。何以知传染？脉不浮者是
也。若误以热药解表，不惟不解，其病反甚而危殆矣。其治之法，自汗宜以苍术白虎汤，无汗宜滑石凉
膈散，热散而愈。其不解者，适其表里微甚，随证治之，而与伤寒之法，皆无异也。
关于伤寒传染的原因，是因为闻到了大量汗液散发出的秽浊毒气，导致精神狂乱、气息紊乱，邪热在体内骤然亢盛，发作于体表而致病。正如《西山记》所说：靠近秽浊之气会损伤人体真气。钱仲阳说：穿着走过粪秽之地的鞋子，不要让它们靠近婴儿，如果婴儿闻到这种气味，会导致小儿急惊风抽搐。孙真人说：骑马远行，到了傍晚应当沐浴、更换衣服，然后才可以接近婴儿，使婴儿不闻到马汗的毒气，否则大多会引发天吊病、急惊风抽搐等症。因此，剥死马的人，因感受了死马的毒气而患上马气病、丁黄病，这都是因为闻到了毒气所致。所以《圣惠方》中有一法：大汗出时，应在门边悬挂药物，以辟除大汗的秽浊毒气，避免伤害他人。世人用艾灸席子角落的做法，都是基于这一道理。多被亲属感染，或是忧愁悲伤、侍奉病人的人，以及从事劳役的人，是因为他们的神气怯弱，容易受到扰乱。如何判断是否传染？脉象不浮就是证据。如果误用热药来解表，不仅不能解除病邪，病情反而会加重并陷入危殆。其治疗方法，自汗者适宜使用苍术白虎汤，无汗者适宜使用滑石凉膈散，待热邪消散即可痊愈。如果病不解，应根据表里证的轻重程度，随证治疗，这与治疗伤寒的方法没有不同。
The cause of the transmission of Shanghan (Cold Damage) lies in inhaling the foul and toxic qi emitted from profuse sweating, which leads to mental agitation and chaotic vital energy. This results in a sudden surge of pathogenic heat internally, manifesting externally as disease. As stated in *Xishan Ji* (Record of Mount West): "Approaching foul air damages the true qi." Qian Zhongyang said: "Shoes that have walked through filth should not be brought near infants; if they smell such odor, it will induce acute convulsions in children." Sun Simiao said: "After riding a horse for a long distance, one must bathe and change clothes before approaching an infant, so that the infant does not smell the toxic vapor of horse sweat; otherwise, conditions such as 'Tiandiao' (a type of childhood convulsion) and acute convulsions often occur." Therefore, those who skin dead horses may contract diseases like "Maqi" (Horse Qi) or "Dinghuang" due to inhaling their toxic vapors, all caused by exposure to these toxins. Thus, *Shenghui Fang* (Prescriptions of Holy Benefit) records a method: when there is profuse sweating, hang medicinal herbs at the door to ward off the foul toxicity of sweat, preventing harm to others. The common practice of moxa-burning the corners of mats derives from this principle. Those frequently infected by relatives, or those who are grieving, caring for patients, or engaged in hard labor, are susceptible because their spirit and vital energy are weak and easily disrupted. How can one know if it is contagious? A pulse that is not floating indicates this. If one mistakenly uses hot-natured drugs to release the exterior, not only will the pathogen not be resolved, but the condition will worsen and become critical. The treatment method is as follows: for cases with spontaneous sweating, Cangzhu Baizhu Tang (Atractylodes Macrocephala and White Tiger Decoction) is appropriate; for cases without sweating, Huashi Liangge San (Talcum Powder and Cool Diaphragm Powder) is appropriate. Once the heat dissipates, recovery occurs. If the disease persists, treat according to the severity of the interior and exterior patterns, following the same principles as treating Shanghan.