The main causes of hot nose breathing include upper respiratory tract infections, acute rhinitis, boils in the nasal cavity, etc. 1. Upper respiratory tract infection: Mostly due to cold or bacterial or viral infection, upper respiratory tract infection occurs. It can cause headache, fever, runny nose, nasal congestion and other symptoms. Due to high body temperature, the temperature of nasal mucosa is relatively elevated, burning when exhaling. 2. Acute rhinitis: Mostly in colds and upper respiratory tract infections, complicated by acute rhinitis, congestion and swelling of nasal mucosa, enlarged turbinates, which can cause hot air coming out of the nose or nasal congestion, sneezing, and even generalized fever, fatigue, muscle aches and pains. 3. Boils in the nasal cavity: when the bacterial infection in the nasal cavity causes the formation of boils, which leads to rupture and congestion of the mucous membrane of the nasal cavity when picking the nose, causing a burning sensation of breathing. Breathing heat in the nose can also be seen in other causes, it is recommended to go to the hospital in time to clarify the cause of the disease and timely treatment.