Nasal congestion in air conditioning is related to cold gas stimulation or allergic rhinitis, and can be relieved by adjusting the room temperature and using medication. 1. Hot and cold gas stimulation: the nasal mucosa due to hot and cold gas stimulation of temporary congestion, edema, resulting in narrowing of the nasal cavity manifested as nasal congestion. Generally no special treatment, adjust the room temperature to the appropriate temperature can relieve the symptoms of nasal congestion. 2. Allergic rhinitis: dust, wool, etc. can induce allergic rhinitis, sneezing, runny, itchy nose or nasal congestion symptoms. Drugs can control symptoms, such as oral cetirizine, loratadine, levocabastine nasal spray nasal anti-allergy; intranasal local application of ephedrine, hydroxymetazoline or oral phenylpropanolamine to relieve nasal mucosal congestion. Keep the living environment clean and dry. If severe nasal congestion occurs after blowing air-conditioning and affects smooth breathing, it is recommended to consult a doctor in time and choose treatment measures according to the doctor’s instruction. The above medications should be used under the guidance of a doctor.