🌿 Folk Prescriptions

End of Heat marks the end of summer heat. “End” implies hiding or cessation, so the name signifies that summer heat is nearing its end. *Monthly Twelve Collections Explanation* says: "In the seventh month, ‘end’ means stopping; summer heat ends here." At this time, the Three Dog Days have passed or are nearly over, hence the phrase “summer heat ends here.” Across China, there is a folk saying: “End of Heat brings cold,” indicating that summer heat gradually fades. However, true autumn coolness has not yet arrived. Afternoon heat remains as intense as in summer, which is why people often say: “Autumn Tiger, as fierce as a tiger.” This reminds us that autumn may still bring hot days, akin to a final flash of summer heat. Gu Tieqing, author of *Qing Jia Lu*, described End of Heat thus: “Locally, after End of Heat, the weather remains hot, lasting another eighteen days before cooling down; the proverb says: ‘Eighteen bowls after End of Heat,’ meaning eighteen days of bathing.” This suggests another eighteen days of sweaty days. At this point, the sun’s ecliptic longitude is 150 degrees. Records state: “When the Big Dipper points to Wu, it is End of Heat; summer heat recedes, hidden and quiet, hence the name.”
From an agricultural perspective, there is the saying: “Grain ripens at End of Heat,” and “Every household busy harvesting rice.” Additionally, lingering autumn rains often arrive after End of Heat, so farmers must pay close attention to weather forecasts and seize every sunny day to complete autumn harvests promptly.
End of Heat is precisely the transitional period from heat to coolness. Nature’s yang energy shifts from dispersion to contraction, and the balance between yin and yang in the human body also changes accordingly. Thus, lifestyle and作息 (daily routines) should be adjusted accordingly. Entering autumn health preservation begins with adjusting sleep patterns—going to bed early and rising early is widely known. Yet few understand the deep emphasis ancient physicians and health practitioners placed on sleep. In fact, scientific health preservation requires a comprehensive grasp of sleep rhythms and methods.
Traditional Chinese medicine’s theory of sleep originates from materialist unity of form and spirit, viewing sleep and wakefulness as a normal physiological state of balance between yin and yang in the body’s waking and sleeping cycles. This includes several aspects:
First, the alternation of day and night yin-yang determines human wakefulness and sleep. Due to celestial movements, nature undergoes continuous yin-yang fluctuations, manifesting as day-night alternation—day is yang, night is yin. Human yin-yang energy also fluctuates accordingly, causing alternating wakefulness and sleep. Wakefulness belongs to yang, governed by yang energy; sleep belongs to yin, governed by yin energy. Since humanity began, our activities have followed a pattern: rise with sunrise, rest with sunset. *Ling Shu·Ying Wei Sheng Hui* states: "When the sun sets, yang energy ends and yin energy takes over. At midnight, all people lie down, called 'joining yin.' At dawn, yin energy ends and yang energy begins, continuing endlessly, synchronized with heaven and earth." *Ling Shu·Kou Wen* further explains: "At midnight, yang energy ends, yin energy dominates, so eyes close." "During daytime, yin energy ends, yang energy dominates, so one awakens."
Second, the physiological basis of sleep lies in the circulation of Ying and Wei qi. The alternation between wakefulness and sleep depends on the movement of Ying qi (nutritive qi circulating inside blood vessels) and Wei qi (defensive qi circulating outside blood vessels), with Wei qi being most relevant. *Ling Shu·Wei Qi Xing* says: "Wei qi circulates around the body fifty times in one day and night, twenty-five times through yang, twenty-five times through yin." Similarly, *Ling Shu·Ying Wei Sheng Hui* states: "Wei qi travels twenty-five times through yin, twenty-five times through yang, divided into day and night. Thus, qi reaches yang and one wakes, reaches yin and one sleeps." Here, "waking" refers to getting up, "sleeping" means falling asleep. Thus, when Wei qi moves through yin, yang energy ends and yin energy dominates, leading to stillness and sleep (the body enters a relatively static state desiring rest); when moving through yang, yin energy ends and yang energy dominates, leading to motion and awakening (the body becomes active and awake). Therefore, human sleep and wakefulness are guided by the mind. Calm mind leads to sleep; active mind leads to wakefulness; extreme emotions make sleep difficult.
Modern medical research divides sleep into four stages: ① falling asleep stage, ② light sleep stage, ③ moderate deep sleep stage, ④ deep sleep stage. During stages ① and ②, one is in a dazed state, easily awakened. Stages ③ and ④ are deep sleep, generally difficult to awaken.
Emphasizing sufficient sleep in autumn health preservation is due to sleep’s excellent health benefits. The *Ten Questions* manuscript unearthed from Ma Wang Dui says: "Sleep is not merely a human necessity. Ducks, geese, snow ducks (Sibugong), eels, fish, and all wriggling creatures require sleep to live... Thus, one night without sleep renders one unable to recover for a hundred days." Clearly, sleep is essential not only for humans but for all living beings. Without normal sleep, normal life functions cannot be maintained.
Sleep serves five main purposes:
First, eliminating fatigue. During sleep, the body’s essence, spirit, and energy retreat inward to the five zang organs. When the zang organs are calm, qi and blood flow smoothly, body temperature, blood pressure, and heart rate decrease, respiration and endocrine activity decline significantly, lowering metabolic rate and restoring physical strength.
Second, protecting the brain. During sleep, the brain’s oxygen consumption drops dramatically. Adequate sleep helps store energy in brain cells, restores mental vigor, and enhances cognitive efficiency.
Third, boosting immunity. Sleep is not only a process of intellectual and physical renewal but also a key method for disease recovery. During sleep, more antigens and antibodies are produced, enhancing resistance. Modern medicine often uses sleep as a therapeutic tool for treating chronic pain and mental disorders.
Fourth, promoting development. Sleep is closely linked to children’s growth. Children grow faster during sleep, so sufficient sleep is essential for height increase.
Fifth, benefiting beauty. Sleep greatly affects skin health. During sleep, skin secretion and cleansing processes intensify, capillary circulation increases, accelerating skin regeneration. Skin fatigue and fine wrinkles caused by overwork are restored during sleep. Thus, sleep is fundamental to skin beauty.
Special note for older adults: With age, the body’s qi, blood, yin, and yang become deficient, leading to insomnia and restless sleep. Ancient health practitioners said: "Insomnia is a major affliction for the elderly." *Ancient and Modern Good Words* advises: "When sleepy, go to bed immediately"—a view consistent with health preservation principles. Moreover, ancient sleep practices emphasized the importance of the "Zi-Wu nap" (sleeping at midnight and noon), believing that at Zi and Wu hours, yin and yang intersect, reaching peak and decline, causing imbalance in internal qi and blood. One must lie down quietly to await restoration. Modern research shows that from midnight to 4 AM, all organ functions drop to their lowest; from 12 PM to 1 PM, the sympathetic nervous system is most fatigued. Statistics indicate that older adults who practice Zi-Wu naps reduce the incidence of cardiovascular and cerebrovascular diseases. Thus, Zi-Wu naps serve both preventive and health-promoting purposes, aligning with health preservation principles.
If one can normally enter all four sleep stages, the brain receives excellent rest, ensuring optimal mental state the next day—exactly what we aim for and a key method in autumn health preservation.
During End of Heat, one should consume foods that clear heat and calm the spirit, such as silver ear fungus, lotus root, lotus seeds, honey, yellow croaker, dried scallops, kelp, sea cucumber, celery, spinach, glutinous rice, sesame, legumes, and dairy products.
Recommended recipes:
Sesame Spinach:
[Ingredients] 500g fresh spinach, 15g roasted sesame, salt, sesame oil, MSG, all in appropriate amounts.
[Preparation] Remove spinach roots, wash thoroughly, blanch briefly in boiling water, then immerse in cold water. Drain and squeeze dry, cut into segments. Place in a bowl, add salt, MSG, sesame oil, mix well, then sprinkle sesame on top.
[Benefits] Nourishes liver and kidneys, opens chest, moisturizes dryness.

Green Pepper Tofu Salad:
[Ingredients] 1 block tofu, 3 green peppers, 10g coriander, sesame oil, salt, MSG, all in appropriate amounts.
[Preparation] Blanch tofu in boiling water, cool, cut into 1 cm cubes. Blanch green peppers briefly, chop finely. Chop coriander. Mix tofu, green peppers, coriander, sesame oil, salt, and MSG together, transfer to a plate.
[Benefits] Invigorates qi, broadens the chest, quenches thirst, moisturizes dryness, clears heat, detoxifies. Especially suitable for poor appetite and lack of appetite.

Lotus Root and Lily Bulb Soup:
[Ingredients] 100g dried lotus root, 75g dried lily bulbs, 75g rock sugar.
[Preparation] Soak lotus root overnight, rinse clean. Soak lily bulbs for 4 hours, rinse clean. Place lotus root and lily bulbs in a pot with water, bring to boil over high heat, add rock sugar, reduce heat, simmer for 40 minutes.
[Benefits] Calms the spirit, nourishes the heart, strengthens the spleen, harmonizes the stomach.

Lily Bulb Preserves:
[Ingredients] 60g fresh lily bulbs, 2 tablespoons honey.
[Preparation] Wash lily bulbs, place in a bowl, pour honey over, steam for 30 minutes, or dry in oven or air-dry. Take in seven portions before bedtime.
[Benefits] Clears heart fire, calms the spirit. Suitable for restless sleep, easy waking, and palpitations.