Go with the flow and take a nap. A nap requires a quiet and comfortable environment. Don't just sleep in the corridor, under the shade, on the grass or on the concrete floor, and don't take a nap in the ventilation, under the electric fan or in the low-temperature air-conditioned room. Because people's body temperature regulation center function declines during sleep, people are not feeling well after waking up, and those who are serious have a cold or heatstroke.
Sit in a chair or sleep at your desk. It's best to lie flat during a nap. Lunch can let more blood enter the gastrointestinal system. When sleeping in a sitting position, the heart rate will slow down, which will easily aggravate the lack of oxygen in the brain, causing dizziness, tinnitus and leg weakness. Sleeping on the table will oppress the chest, affect breathing, increase the burden on the heart and lungs, and it is easy to dream; The pressure of the head on the arm will also affect blood circulation and nerve conduction, making the upper limbs numb or numb; Sticking your eyes to your arm will press your eyes, and after waking up, you will have temporary blurred vision, which will be harmful to your eyes after a long time.