It means, don't lie down and sit against the wind. Chinese medicine believes that wind is the source of all diseases. It is easy to get sick if you rest in the tuyere for a long time. There is a legend here. Legend has it that there is a family whose ancestors did not live to be 40 years old. Bian Que went to see a doctor for this family and found that there was nothing strange about this family. Then he went to the place where the family rested. I found them all sleeping by the window with their heads facing the window. So I told the family to sleep somewhere else or block the window. After the family blocked the window, no one died for no reason.