Why is it hot and boring ... I have no spirit all day and always feel sleepy ~ ~

I think so. In summer, the temperature is high, and the body's blood circulation is rich in heat dissipation, so the blood supply to the brain is insufficient and it is easy to be awake and sleepy. Muscle and blood are also insufficient, and I feel weak. On the other hand, muscle movement generates heat. In order to keep the body temperature not too high, a series of complex neuromodulation will relax the muscles and will not produce heat, so the whole body is weak. Not only people, but almost all animals are like this. Look at the lions in the animal world. They never hunt in the hot sun. They all slept in the shade until dusk. This is conducive to the self-preservation of life. According to my current knowledge, this is analysis.