Cold Dew is the seventeenth solar term in the Chinese lunar calendar, and it is the fifth solar term of autumn, indicating the official start of the autumn season; it occurs between October 7th and 9th each year in the Gregorian calendar. The arrival of Cold Dew also means that winter is not far away from us.
During the Cold Dew period, the temperature continues to drop in most parts of southern China. The average daily temperature in the southern regions is often below 20°C, and even in the areas along the Yangtze River, the mercury column rarely rises above 30°C, while the minimum temperature can drop below 10°C. In the northwestern plateau, except for a few low-lying river valleys, the five-day average temperature is generally below 10°C, which, according to the standard for dividing seasons in climatology, is already winter. A thousand miles of frost cover, completely different from the autumn scenery in the south.

Starting from the "Cold Dew" period, rainfall gradually decreases, the weather becomes dry, and the day is hot while the night is cool. From a traditional Chinese medicine perspective, the biggest characteristic of this season in the southern climate is the dominance of "dryness" evil, which easily harms the lungs and stomach. During this period, people's sweat evaporates quickly, so skin dryness, increased wrinkles, dry mouth and throat, dry cough with little phlegm, and even hair loss and constipation may occur. Therefore, the focus of health preservation at this time is to nourish yin, prevent dryness, moisten the lungs, and benefit the stomach.
It is necessary to avoid excessive physical exertion or overwork that can deplete vital energy, body fluids, and moisture. In terms of diet, it is advisable to eat fewer spicy, stimulating, fragrant, and roasted foods, and instead consume more foods with nourishing yin, moistening dryness, benefiting the stomach, and generating body fluids, such as sesame, walnuts, white fungus, radish, tomato, lotus root, milk, lily, and adenosma. At the same time, maintain a certain level of humidity indoors, pay attention to replenishing water, and eat fruits like pears, bananas, honey melons, apples, water persimmons, and grapes. In addition, it is important to apply moisturizing cream to protect the skin and prevent cracking.