Bai Lu is the fifteenth solar term of the year. Ancient Chinese divided Bai Lu into three periods: "First period, swallows arrive; second period, the small bird returns; third period, flocks of birds store food." This means that during the Bai Lu solar term, migratory birds such as swallows and swallows fly south to avoid the cold, and various birds begin to store dry fruits and grains for winter. It can be seen that Bai Lu actually symbolizes the cooling of the weather.
In traditional Chinese medicine, the climate changes in the four seasons are called "wind, cold, heat, dampness, dryness, and fire." The climate change in autumn is "dryness." The health care during the Bai Lu solar term should focus on generating saliva and moistening dryness. At this time, people should follow the natural laws and collect their thoughts and energy.

When the season reaches Chushu, the temperature enters a stage of significant change, gradually decreasing, and it is no longer sweltering. This change in the season naturally reflects in agricultural activities. The many practical proverbs left by ancient people, such as "A fall rain brings a bit of coolness," "Three rains in the beginning of autumn make the cotton fan hang high," "The weather is cool at the beginning of autumn and Chushu," and "Chushu is not hot," directly describe the climate change during the "Chushu" period.
However, overall, the climate characteristics during the Chushu period are that it is hot during the day but cool in the morning and evening, with a large temperature difference between day and night, less precipitation, and low air humidity. In such an environment, people are prone to symptoms of dryness, such as dry mouth and lips. Therefore, clothes should not be worn too much, and one should avoid overheating, but also should not get too cold. So, during this period, attention should be paid to preventing dryness, and both diet and daily life should be well adjusted.