周禹载曰。夏日暑湿交蒸。人多中暑。证与热病相似。首宜以脉辨之。夫热病之脉
必盛。中暑之脉必虚。盖寒伤形而不伤气。所以脉盛。暑伤气而不伤形。所以脉虚。
然又有弦细芤迟之脉者何也。人当暑月必多汗。汗多则脉虚。此其常也。守真曰。
热为阳中之至阳。以热伤气。则汗自出。病虽为热。脉不能实。而反虚弱也。若汗出
当风。闭其汗孔。则风与汗湿留泊肌腠。脉故弦细。或虚风不作郁热。表虚仍自汗出者。脉必芤迟也。统
而言之曰虚。分而言之曰弦细芤迟。其不以浮大之脉。混入虚脉之中。称为暑病之脉也。
张凤逵曰。刘复真云。暑脉虚而微弱。按之无力。又脉来隐伏。弦细芤迟。皆暑脉也。
脉虚身热。得之伤暑中 。脉虚而微者是也。寒病传经。故脉日变。温热不传经。故
脉不变。寒病浮洪有力者易治。芤细无力者难治。无脉者不治。若温热则不然。温
有一二部无脉者。暑热有三四部无脉者。被火所逼勒而藏伏耳。非绝无也。于病
无妨。攻之亦易。医人一切惊走不知。照经用辛寒药。火散而脉起。脉起而病愈。徒
骇何益乎。要在辨之详耳。盖温热病发在一二经。始终止在此一二经。更不传递
别经者。其一二经或洪数。则别经弱且伏。根据经络调之。则洪者平。伏者起。乃愈征
也。昔在万历丁未三月间。予寓京师。备员太仓库瘥。忽一日吏部同乡刘蒲亭驰
报曰。病剧求救。予就其寓。吏部同僚诸公环守之。已备后事。谵语捻衣。不寐者已
七八日。御医院吴思泉名医也。偕医数人治之。予诊其脉。止关脉洪大。其余皆伏。
乃书方竹叶石膏汤。诸公皆惊曰。吴等已煎附子理中汤。何冰炭如是。予诘之。吴
曰。阳证阴脉。故用附子。予曰。两关洪大。此阳脉也。其余经为火所伏。非阴脉也。吴
厉声相争。予亦动色自任。诸公从之。一剂甫时。即止谵语。就寐片时。予视其脉已
洪者乎。而伏者起。诸公相视曰。此真张仲景也。又用辛凉药调理痊愈。脉证有相
合者易知。有相左者难知。脉明而后可以辨证。证真而后可以施药。要在虚心细
察。不可执已见。而以百药尝试。令命在反掌间也。慎之慎之。
周禹载说：夏季暑气与湿气交相蒸腾，人们容易患中暑。其症状与热病相似，首先应当通过脉象来辨别。热病的脉象必然盛大，中暑的脉象必然虚弱。这是因为寒邪损伤形体而不损伤气，所以脉象盛大；暑邪损伤气而不损伤形体，所以脉象虚弱。然而又有出现弦、细、芤、迟脉的情况，这是为什么呢？人在暑月必定多汗，汗出过多则脉象虚弱，这是常理。刘守真说：热是阳中的至阳之邪，因热伤气，则汗自出。病虽为热证，但脉象不能充实，反而虚弱。如果出汗时当风，导致汗孔闭塞，那么风邪与汗湿滞留于肌腠之间，脉象因此呈现弦细。或者虚风不作而郁热内生，表虚仍然自汗出的，脉象必然呈现芤迟。统而言之称为“虚”，分而言之则是弦、细、芤、迟。不将浮大之脉混入虚脉之中，从而误称为暑病的脉象。
张凤逵说：刘复真（即刘守真）曾说：暑脉虚而微弱，按之无力。又脉象隐伏，或呈弦、细、芤、迟，这些都是暑脉的表现。脉虚身热，是由于伤暑所致，脉虚而微弱的就是这种情况。寒病会传经，所以脉象每日变化；温热病不传经，所以脉象不变。寒病中脉象浮洪有力的容易治疗，芤细无力的难治，无脉的不可治。但温热病就不是这样了。温病有一两部无脉的，暑热病有三四部无脉的，这是因为被火邪逼迫而潜藏伏匿罢了，并非真的没有脉。这对病情没有妨碍，攻邪也容易。医生们全都惊慌失措，不知此理，若照经方使用辛寒药物，火散则脉起，脉起则病愈。徒然惊恐有什么益处呢？关键在于详细辨别。因为温热病发病在一二条经络，始终只在此一二条经络，不再传递到其他经络。这一二条经络的脉象或洪数，则其他经络的脉象弱且伏。根据经络进行调理，则洪大的脉象平和，伏匿的脉象升起，这才是痊愈的征象。
过去在万历丁未年三月间，我寓居京城，在太仓库担任闲职。忽然有一天，吏部同乡刘蒲亭骑马赶来报告说：病情危重，请求救助。我去到他住处，吏部的同僚各位先生都围守在那里，已经准备好后事。患者胡言乱语、捻弄衣角，不睡觉已经有七八天了。御医院的吴思泉是一位名医，他带着几位医生一起诊治。我诊察他的脉象，只有关脉洪大，其余部位的脉象都伏匿。于是开出处方竹叶石膏汤。各位先生都惊讶地说：“吴医生等人已经煎好了附子理中汤，为什么冰炭如此不同？”我责问他们。吴医生说：“阳证见阴脉，所以用附子。”我说：“两关脉洪大，这是阳脉啊。其余经络的脉象是被火邪伏匿，并不是阴脉。”吴医生厉声争辩，我也神色严肃地承担责任。各位先生听从了我的建议。一剂药刚服下不久，患者的谵语就停止了，能睡一会儿。我查看他的脉象，原来洪大的脉象缓和了，伏匿的脉象升起了。各位先生互相看着说：“这真是张仲景再世啊！”后来再用辛凉药物调理而痊愈。脉象与症状有相符的容易判断，有相违背的难以判断。只有脉象明了之后才可以辨证，证候真实之后才可以用药。关键在于虚心细致观察，不可固执己见，而以各种药物尝试，让性命在反掌之间丧失。谨慎啊，谨慎啊。
Zhou Yu Zai said: In summer, heat and dampness steam and mix together, and people are prone to heatstroke. The symptoms resemble those of febrile diseases (Re Bing), so one must first differentiate them by pulse. The pulse in febrile disease is necessarily vigorous (Sheng), whereas the pulse in heatstroke is necessarily deficient (Xu). This is because cold damages the form but not Qi, hence the pulse is vigorous; heat damages Qi but not the form, hence the pulse is deficient. However, why do pulses such as cord-like (Xian), fine (Xi), hollow (Kou), and slow (Chi) appear? During the hot months, people sweat profusely; excessive sweating leads to a deficient pulse, which is the normal state. Liu Shou Zhen said: Heat is the supreme Yang within Yang. When heat damages Qi, spontaneous sweating occurs. Although the disease is due to heat, the pulse cannot be full but is instead weak and deficient. If wind strikes while sweating, closing the sweat pores, wind and dampness from sweat remain stagnant in the muscle interstices (Ji Cou), causing the pulse to become cord-like and fine. Or, if deficiency-wind does not arise but latent heat accumulates, and the exterior deficiency still causes spontaneous sweating, the pulse will necessarily be hollow and slow. Generally speaking, it is called "deficient"; specifically, it is cord-like, fine, hollow, or slow. One should not confuse floating and large pulses with deficient pulses, thereby misidentifying them as the pulse of heat disease.
Zhang Feng Kui said: Liu Fu Zhen (Liu Shou Zhen) stated: The pulse of heat is deficient and faint, powerless upon pressure. Also, the pulse may be hidden/submerged (Yin Fu), or cord-like, fine, hollow, and slow; all these are pulses of heat. A deficient pulse with body heat results from injury by heat (Shang Shu); a pulse that is deficient and faint is indicative of this. Cold diseases transmit through meridians, so the pulse changes daily; warm-heat diseases do not transmit through meridians, so the pulse remains unchanged. In cold diseases, a floating and surging pulse with strength is easy to treat; a hollow and fine pulse without strength is difficult to treat; an absent pulse is untreatable. However, warm-heat diseases are different. In warm disease, there may be no pulse in one or two positions; in heatstroke, there may be no pulse in three or four positions. This is because the pulse is forced into hiding by fire/heat pathogens, not because it is truly absent. This poses no harm to the condition, and attacking the pathogen is relatively easy. Physicians often panic and fail to understand this. If one prescribes acrid-cold herbs according to the classic texts, the fire dissipates, the pulse rises, and the disease cures. What benefit is there in mere terror? The key lies in detailed differentiation. Warm-heat diseases originate in one or two meridians and remain confined to them, not transmitting to others. The pulse in these affected meridians may be surging and rapid, while the pulse in other meridians is weak and submerged. By regulating according to the meridians, the surging pulse becomes balanced, and the submerged pulse rises, indicating recovery.
In the third month of Ding Wei year during the Wanli era, I resided in the capital, holding a minor post in the Ministry of Revenue (Tai Cang Ku). Suddenly, my fellow official from Li Bu, Liu Puting, rode over reporting a critical illness and seeking help. I went to his residence, where colleagues from the Ministry of Personnel were gathered around, having already prepared funeral arrangements. The patient was delirious (Chan Yu), picking at clothes, and had not slept for seven or eight days. Wu Si Quan, a famous physician from the Imperial Medical Academy (Yu Yi Yuan), treated him along with several other doctors. I palpated his pulse and found only the Guan position to be surging and large, while the rest were submerged. I then prescribed Zhu Ye Shi Gao Tang (Bamboo Leaf and Gypsum Decoction). The gentlemen were astonished, saying, "Dr. Wu has already decocted Fu Zi Li Zhong Tang (Aconite Root and Magnolia Bark Decoction). Why is your approach so contrary?" I questioned them. Dr. Wu said, "Yang syndrome presenting with Yin pulse necessitates the use of Aconite." I replied, "The bilateral Guan pulses are surging and large; this is a Yang pulse. The pulses in the other positions are suppressed by fire/heat, not Yin pulses." Dr. Wu argued loudly, but I stood firm with a serious demeanor. The gentlemen followed my advice. After just one dose, the delirium ceased, and he slept for a short while. I checked his pulse again: the previously surging pulse had softened, and the submerged pulses had risen. The gentlemen looked at each other and said, "This is truly Zhang Zhong Jing reborn!" Subsequently, he recovered after being regulated with acrid-cool medicines. When pulse and symptoms correspond, diagnosis is easy; when they contradict, it is difficult. Only when the pulse is clear can one differentiate the syndrome; only when the syndrome is true can one administer medicine. One must observe with an open mind and carefully, not adhering stubbornly to preconceived notions and experimenting with various drugs, risking life in the blink of an eye. Be cautious, be cautious.