Rain Water is the second solar term of the year, coming after the first 15 days of the Start of Spring. The period from Rain Water to Awakening of Insects lasts 15 days and is divided into three "hou" (候). The *Huangdi Neijing·Suwen·Linglan Midian Lun* states: "Five days are called a hou; three hou are called a qi (气); six qi are called a season; and four seasons are called a year." Five days constitute a hou, three hou constitute a qi, six qi (90 days in total) make up a season, and the four seasons—spring, summer, autumn, and winter—total 360 days, which is a year. During the first hou of Rain Water, the river ice thaws, and fish begin to surface. In the second hou, wild geese start to migrate from south to north. In the third hou, plants and trees begin to sprout. During the Rain Water period, special attention should be paid to the phenomenon of "spring cold snaps" (倒春寒). After Rain Water, the moisture in the air increases, causing the temperature to be not only low but also damp within the cold. This damp and cold climate has a certain impact on the body's internal organs and joints. Health preservation should note the following matters:
One, do not remove outer clothing too early. "Dry cold freezes the flesh, while damp cold penetrates the bones." As the spring energy surges, people with a relatively hot body temperature may feel the urge to remove their outer clothes. This allows the body's heat to escape, and damp-cold enters the body and bones, easily causing damage to the joints and bones.
Two, the elderly and those with weak constitutions should not use cold water. According to Chinese Five Elements theory, water corresponds to the kidneys, and the kidneys govern the bones. During the Rain Water season, if the elderly or those with weak constitutions wash their face and hands with cold water, damp-cold can easily invade the joints. Without sufficient yang energy to drive the cold out, the damp-cold stagnates in the hands, causing the fingers to ache, and in severe cases, to become deformed. If it stagnates in the head, it can easily lead to headaches.
Three, dry your hair promptly after washing. After washing your hair, you should blow it dry with a hairdryer. Otherwise, the moisture in the hairline cools down. "Similar qi attracts," causing damp-cold to gather in the head, penetrating from the surface to the inside of the skull, leading to headaches. If the hair is not dry and is then blown by cold wind, it is easy to develop a condition similar to "migraine" (偏头风).
Four, it is best to eat foods that are neutral in nature. "Spring cold snaps" can easily cause stagnation and blockage of heat in the internal organs. Therefore, it is not advisable to eat hot and dry foods, as this would be "like pouring oil on a fire." Stagnated heat makes people "crave coolness." However, consuming too many cold foods will, again through the principle of "similar qi attracting," cause damp-cold to harm the internal organs, leading to imbalances such as stomach cold, stomach coolness, and diarrhea. Therefore, it is best to maintain a moderate diet, eating hot meals, but avoiding or being cautious with pungent foods like chili peppers and consuming less or no warm and hot alcoholic beverages like baijiu.