恶寒者，风寒客于营卫之中也。惟其风寒客于营卫，则洒淅然恶寒也。惟其营卫之受风寒，则啬然
不欲舒也。其恶寒者，非恶寒热之寒，又非恶风也。盖恶风、见风则恶，若居密室之内，帏帐之中，则坦
然自舒也。至于恶寒者，虽不见风，亦自里寒虽身大热，亦欲近衣，始发之间，战栗鼓颔，甚则体振，肌
肤粟起，毫毛毕直，虽在帏帐之中，重衣厚被，亦不能御其寒也。且寒热之寒，谓寒热更作，热至则寒
无矣。其恶寒者，虽身发热，而不欲去衣，甚至向火覆被，犹不遏其寒也。所以然者，由阴气上入阳中，
或阳微，或风虚相搏所致。恶寒一切属表，若下症悉具而微恶寒者，是表犹未解，当先解表，乃可攻
里也。经曰、发热恶寒、发于阳，无热恶寒、发于阴。如伤寒或已发热，或未发热，若先恶寒，必继之以发
热，此则发于阳也。若恶寒而蜷卧，脉细而紧，此则发于阴也。在阳者可发汗，在阴者可温里。恶寒虽
悉属表，而在表自有虚实之别。若汗出而恶寒者，为表虚，可解肌。无汗而恶寒者，为表实，可发活。如
汗后仍不解，反恶者。虚故也，芍药甘草附子汤之。如或少阴病，恶寒而蜷卧，手足厥冷，自利烦躁，
脉不至者，又为不治之症。
按发热恶寒，明是伤寒之候，然亦有近似伤寒者。如脉浮而数，发热恶寒，是伤寒症也，若脉浮而发热恶寒，
或有痛处，是痈疽症也。脉浮而涩，发热恶寒，或膈实呕吐，噫嗳吞酸，是伤食症也。脉浮而弦，发热恶寒，或恶
食，是欲作疟也。由是观之，发热恶寒之症，岂同一而语哉。
恶寒，是风寒邪气侵袭营卫所致。正因为风寒邪气客居在营卫之中，所以会出现洒淅然（形容寒冷颤抖的样子）的恶寒感。正因为营卫受到风寒侵袭，所以会感到紧缩收敛而不愿舒展。这种恶寒，并不是指对寒热交替中“寒”的感觉，也不是单纯的怕风。所谓怕风，是指见到风就觉得难受，如果待在密室之内、帷帐之中，就会坦然自在地感到舒适。至于恶寒，即使不见风，身体内部也会感到寒冷；虽然身体表面很热，却想要靠近衣物保暖。在发病初期，会出现战栗、下巴打颤，严重时全身震颤，皮肤起鸡皮疙瘩，毫毛竖立，即使身处帷帐之中，穿着厚衣盖着厚被，也无法抵御这种寒冷。而且，寒热病中的“寒”，是指寒与热交替发作，当热势到来时，寒的感觉就消失了。而恶寒，即使身体发热，也不愿意脱去衣服，甚至对着火源、盖上被子，仍然无法遏制体内的寒冷。之所以这样，是因为阴气上入阳分，或者是阳气微弱，或者是风邪与虚证相互搏结所致。恶寒一概属于表证，如果具备所有的里实证症状，但只有轻微的恶寒，说明表证仍未解除，应当先解表，然后才能攻里。《内经》说：“发热恶寒，是发于阳经；无热恶寒，是发于阴经。”例如伤寒症，有的已经发热，有的尚未发热，如果先出现恶寒，随后必然继之以发热，这属于发于阳经。如果出现恶寒且身体蜷缩卧倒，脉象细而紧，这属于发于阴经。病在阳经的可以用发汗法治疗，病在阴经的可以用温里法治疗。恶寒虽然都属于表证，但在表证中自有虚实之分。如果出汗且恶寒，属于表虚证，可以用解肌法治疗；如果无汗且恶寒，属于表实证，可以用发汗法治疗。如果发汗后病情仍未缓解，反而更加恶寒，这是因为正气虚弱，应用芍药甘草附子汤治疗。如果患有少阴病，出现恶寒、蜷缩卧倒、手脚冰凉、自发性腹泻、烦躁不安、脉搏摸不到的情况，又属于不治之症。
按语：发热恶寒，明明是伤寒的症状，但也有近似伤寒的其他病症。例如脉象浮而数，伴有发热恶寒，这是伤寒症；如果脉象浮而发热恶寒，或者身体某处有疼痛，这是痈疽症；如果脉象浮而涩，伴有发热恶寒，或者胸膈痞满呕吐、嗳气吞酸，这是伤食症；如果脉象浮而弦，伴有发热恶寒，或者厌恶食物，这是将要发作疟疾。由此看来，发热恶寒这类症状，难道能一概而论吗？
Chills (aversion to cold) result from Wind-Cold pathogens invading the Ying and Wei (Defensive) levels. Because Wind-Cold resides within the Ying and Wei, one experiences chills with shivering (sa xi). Because the Ying and Wei are affected by Wind-Cold, there is a sensation of tightness and reluctance to stretch or relax. This "chills" is not the "cold" phase of alternating chills and fever, nor is it simply aversion to wind. Aversion to wind means discomfort upon exposure to wind; however, if one stays in a sealed room or under curtains, they feel comfortable and relaxed. In contrast, chills involve an internal sensation of cold even without wind exposure. Although the body surface may be hot, the patient desires to keep warm with clothing. At the onset, there may be tremors and jaw quivering; in severe cases, whole-body shaking, cutis anserina (goosebumps), and erect hair occur. Even under thick blankets in a curtained room, the cold cannot be dispelled. Furthermore, the "cold" in alternating chills and fever refers to the cold phase preceding fever; when heat arrives, the cold sensation ceases. However, with true chills, even if the body is feverish, the patient refuses to remove clothes, and even facing fire or covering up with quilts fails to alleviate the cold. This occurs because Yin Qi invades the Yang level, or due to deficient Yang, or the interplay between Wind pathogen and deficiency. Chills generally belong to Exterior syndromes. If all signs of Interior excess are present but accompanied by slight chills, the Exterior has not yet resolved; one must first release the Exterior before attacking the Interior. The Classics state: "Fever with chills indicates disease originating in Yang; absence of fever with chills indicates disease originating in Yin." For example, in Cold Damage (Shang Han), whether fever has already appeared or not, if chills precede and are followed by fever, this originates in Yang. If chills are accompanied by curling up in bed, with a fine and tight pulse, this originates in Yin. Diseases in Yang can be treated with sweating methods; diseases in Yin require warming the Interior. Although chills generally belong to the Exterior, there are Deficiency and Excess distinctions within the Exterior. Sweating with chills indicates Exterior Deficiency, treatable by releasing the muscle layer (jie ji); no sweating with chills indicates Exterior Excess, treatable by inducing sweating (fa han). If symptoms persist after sweating and chills worsen, it is due to deficiency, and Shaoyao Gancao Fuzi Tang (Peony, Licorice, and Aconite Decoction) should be administered. If Shaoyin disease presents with chills, curling up, cold extremities, spontaneous diarrhea, irritability, and an imperceptible pulse, it is considered incurable.
Note: Fever with chills is clearly a sign of Cold Damage, yet other conditions mimic it. For instance, a floating and rapid pulse with fever and chills indicates Cold Damage. A floating pulse with fever, chills, and localized pain indicates carbuncles and sores (yong ju). A floating and choppy pulse with fever, chills, chest fullness, vomiting, belching, and acid regurgitation indicates food retention. A floating and wiry pulse with fever, chills, and food aversion indicates impending malaria. Thus, can fever and chills be discussed as a single uniform entity?