The incubation period of a cold is short, usually about 3 days, and during the incubation period symptoms such as weakness, drowsiness and poor appetite may occur. The length of the incubation period is related to the concentration of the virus, the time of exposure, the amount of exposure, and your own immunity. The incubation period will be shortened if you have been exposed to a large concentration of the virus, for a long time, for a large amount of time, or if your immune system is weak, and you will soon develop the symptoms of the common cold. The common cold is a self-healing disease and usually gets better in 5 to 7 days. If symptoms of the incubation period appear, you need to rest, ensure sufficient sleep, and eat less spicy, stimulating, greasy, cold food. Normally, you can exercise more to improve immunity and reduce the possibility of illness.