Lu Tingzhen Zixian of Chongming authored this; Qiu Shiyun Yuchu of Shaoxing re-collated it.

I have observed that among the numerous medical books, there is no mention of "Fu Shu" (Latent Summerheat). Only in *Jiren Bian* (Compilation of Self-Reliance) is there a phrase stating, "Late onset in autumn, treated with methods for exogenous patterns," which led to the establishment of the term "Fu Shu." This is because during the height of summer, sweat flows and qi becomes sparse, joints become flaccid and swollen. If there are gaps or weaknesses, pathogenic factors enter due to deficiency. As stated in *Neijing* (The Inner Canon), "The most deficient places are where pathogens reside"(1). It also states: Wind injury in spring leads to undigested stool diarrhea in summer; Summerheat injury in summer leads to malaria in autumn; Dryness injury in autumn leads to cough in winter; Cold injury in winter leads to warm diseases in spring. Thus, it can be known that latent qi from the four seasons can all cause disease. Even latent cold, latent wind, and latent dryness can be named and treated alongside latent summerheat. Therefore, Spring Warmth is caused by latent cold from winter; Intestinal Wind is caused by latent wind from spring; Malaria and dysentery are caused by latent summerheat from summer; Cough is caused by latent dryness from autumn. By analogy, one can deduce others. The ancients' legislation for treating diseases was indeed well-founded, but later generations failed to examine these words carefully and paid little attention. I have devoted myself to this field for twenty years under a false reputation; how dare I make rash comments? (1) "The most deficient places are where pathogens reside": According to *Neijing*, this text exists, but not this exact phrasing. (2) Can: Here pronunciation and meaning are identical to Sun (undigested stool diarrhea). (3) Zao: In *Neijing*, it is uniformly written as Shi (Dampness). Since former sages had already initiated this line of inquiry, and later generations did not exhaust its principles, I merely extend it slightly, leaving it for selection, so that one may infer the origin of the name "Fu Shu." Moreover, not only can one infer the origin of the name, but also the etiology of the disease and its treatment.

When Fu Shu manifests in autumn, symptoms include headache, absence of sweating, aversion to cold and fever, body pain, chest and abdominal fullness and oppression, or vomiting and diarrhea. This indicates that new exogenous pathogens are triggering latent summerheat. Xiangru Yin (Elsholtzia Decoction) combined with Zhengqi San (Regulating Qi Powder) should be used to harmonize both exterior and interior.
This serves as the outline for Fu Shu. Generally, summerheat latent during summer, when exposed to the chilly cold of autumn, invades the Couli (interstitial spaces/skin pores), thereby stirring up internal pathogens. Thus, absence of sweating, headache, body ache, fever, and aversion to cold are signs of new external contraction, indicating the disease remains at the Exterior level. Chest and abdominal fullness/oppression, along with alternating vomiting and diarrhea, indicate the activation of latent summerheat, involving the Interior level. In general diagnostic assessment, one must clearly distinguish between new contraction and latent pathogens, determining what exists and what does not, and assessing their relative severity. Therefore, Xiangru Yin combined with Zhengqi San is employed. Elsholtzia, Agastache, Perilla Leaf, Angelica Dahurica, and Platycodon use bitter and acrid properties to travel to the exterior and disperse new pathogens. Pinellia, Magnolia Bark, Tangerine Peel, Areca Peel, and Medicated Leaven use acrid and warm properties to regulate the middle jiao and resolve latent pathogens. Consequently, the interior and exterior are thoroughly unblocked, and pathogens are naturally dispersed and excreted.