First, in just four words,? First of all? Of the head. Simply put, you can't cover your head with a quilt when you sleep. Why is there such a requirement? Because the head is covered with a quilt, it is easy to cause air circulation and occlusion, resulting in poor breathing. If it is a child, it is easy to suffocate. Under the long-term cover of the quilt, our sleep quality will be seriously affected, which will lead to the decline of blood circulation function in the head because there is no oxygen, and then lead to the harm of diseases to the body.
Second, in this sentence, North? It means north. As we all know, the ancients always attached great importance to orientation, and geomantic omen is also an important factor affecting the orientation of houses. In ancient buildings, it is generally said that the north faces south. Of course, when we sleep, the direction is also very important. The ancients believed that the north was cold and windy since ancient times. If you sleep in the north, you will be attacked by the cold in the north, which will have a great impact on your health.
Today, such a statement seems to no longer exist. In real life, as long as you meet the requirements in light and comfort, you can create an excellent sleep state. In fact, the wisdom of the ancients has never been underestimated. The appearance of these two sentences has more or less its reason and experience. But the ancients also had some feudal superstitious ideas, which was not a great truth. In the usual study, we must distinguish them. Have a good dream!