There is a saying in Huangdi Neijing: "Yang, beyond one day, is prosperous, while the day is strong and the day is weak in the west." This shows that people have the strongest yang in the morning and the weakest yang at night.
Therefore, people who pay attention to health will "have long hair and walk slowly in the court" when the yang rises in the morning, and gradually accumulate the yang. At this time, if you take a bath, especially if the water temperature is cold, it is easy to hurt the yang. Moreover, when people just wake up, the blood circulation is slow and the various functions of the body have not fully awakened. When the skin is stimulated by water, the capillaries suddenly open, and the external moisture and cold will suddenly enter the body.
At night, yin rises and yang sinks, and the body surface lacks protection. At this time, taking a bath will make it easy for moisture to enter the body, especially when the hair is completely dry. The residual moisture on the scalp will quietly enter the body when you sleep, causing the body to be wet. Moreover, the temperature difference between day and night in autumn is large, and the temperature becomes lower at night. Taking a bath too late is easy to catch a cold. Try not to take a shower at nine o'clock in the autumn night.
In addition, don't rush to take a shower just after exercise. When taking a bath, people's capillaries will open, and the sweat of the body will enter the body together when taking a bath, resulting in an increase in humidity. The correct way is to take a bath after exercise until the sweat on your body is basically dry.
To sum up, it is best to take a bath in autumn from two hours after meals to two hours before going to bed, and between eight and nine o'clock.