Why does the face get hot and red when sleeping in the classroom when the weather is cold?

This is because the temperature difference between indoor and outdoor is relatively large, and the body temperature rises after coming in. Blushing means that due to the change of temperature or mood, it is easier to turn red, darker and lasts longer than others. There are blood vessels in the skin, which will expand or contract under the influence of nerve factors, especially the capillaries in the cheeks are rich.

Guiding opinions:

Hello, this is because the temperature difference between indoor and outdoor is relatively large, and the body temperature rises after coming in. Blushing means that it is easier to turn red, darker and last longer than others because of temperature or emotional changes. There are blood vessels in the skin, which will expand or contract under the influence of nerve factors, especially the capillaries in the cheeks. Blushing is usually caused by the dilation of small blood vessels in the face, which may be related to skin irritation. Don't worry, it's normal.