Using air conditioning set too low, or staying in an air-conditioned room for a long time, can easily cause a cold due to the lack of air circulation. When a person's immune function is low, it is easy for viruses or bacteria to invade the respiratory tract, causing symptoms such as nasal congestion, runny nose, fever, headache, and dizziness. In the case of a common cold, it might be a heat-type cold or it could be a cold-type cold. Common colds are usually caused by viral infections of the respiratory tract, leading to clinical symptoms of discomfort. On the other hand, air conditioning colds often occur due to the air conditioning being set too cold, leading to cold-induced symptoms. Thus, there is a distinct difference between air conditioning colds and common colds, with the systemic symptoms caused by air conditioning colds being relatively more severe.