As the temperature decreases, most areas in the north begin to enter the heating period. If the room temperature is too high and the humidity is too low, people will feel uncomfortable, and even have dry lips, bleeding nostrils, dry and itchy throat and other burning phenomena. When the air is dry, the propagation speed of influenza virus and gram-positive bacteria that can cause infection is accelerated, and it is also easy to spread with the dust in the air to cause disease. So how to adjust the living environment during the heating period to prevent disease and eliminate fire? What food can nourish yin and produce saliva?