Opening windows for colds is for specific situations, such as except for colder weather, proper opening of windows for ventilation can reduce the large number of bacteria, viruses, fungi and other pathogenic bacteria in the indoor air, and the air will be fresh, which is good for recovery from illness and can also prevent infection to other family members. In winter if the windows are open for ventilation, it may lower the indoor temperature and these cool air may aggravate the cold. So you should pay attention to the indoor temperature and choose whether to open the windows for ventilation according to the indoor temperature. Normally, the detoxification system of the nasal cavity itself is able to transport the disease-causing bacteria to the nasopharynx within 15-30 minutes, and then eventually to the stomach for digestion. The number of viruses at this time is always kept within the range that the nasal immune system can tolerate, so you will not get sick. However, some triggering factors, such as cold, rain, etc., these can reduce the detoxification function in the nasal cavity. So corresponding to the cold, if the indoor temperature is low, and also open the window to ventilate, it aggravates the symptoms of cold. Therefore, it is necessary to measure whether to open the windows for ventilation according to the indoor temperature.