20℃: the best room temperature and sleeping temperature. In spring and autumn, it is the most comfortable temperature to keep the room temperature around 20℃. Because when humans first appeared more than 2 million years ago, the average temperature during the day was below 25℃, which was most conducive to the body to emit excess heat. At the same time, 20℃ is also the best sleeping temperature. When the room temperature is above 24℃, sleep will become shallow, and the number of body movements and waking up during sleep will increase. When the sleep temperature is lower than 18℃, it is easy to wake up and not easy to enter deep sleep. Therefore, the bedroom room temperature is generally around 20℃ and the humidity is around 60%. If it is an office, it is best to keep the temperature constant at 17℃, which is the most suitable environmental temperature for human thinking and the best learning temperature. When the room temperature exceeds 25℃, the human body begins to absorb heat from the outside, and you will feel hot. If the room temperature exceeds 35℃, the sweat glands of the human body will start, and you will feel your heart beating faster, blood circulation faster, dizzy, unwell, tired and sleepy. On the contrary, when the room temperature is below 4℃, you will feel cold; When the temperature is 8℃~ 18℃, the human body will radiate heat.