A runny nose at the first sign of heat may be caused by vasomotor rhinitis. Vasomotor rhinitis is a kind of nasal mucosal hyperresponsive rhinopathy with unknown pathogenesis and induced by a variety of nonspecific stimuli. Stress, anxiety, and sudden changes in ambient temperature cause excessive release of parasympathetic neurotransmitters or cause nonspecific release of histamine. When the ambient temperature rises, it may lead to vasodilation, increased glandular secretion, and a runny nose. The clinical manifestations of vasomotor rhinitis are three main symptoms: nasal congestion, nasal overflow, and sneezing, often with one symptom predominating. Therefore, there are nasal congestion type, nasal overflow type and sneezing type. Treatment is based on drug therapy. Intranasal glucocorticoids, such as mometasone furoate nasal spray; intranasal antihistamines, such as azelastine hydrochloride nasal spray; intranasal anticholinergics, such as 0.03% ipratropium bromide nasal spray; nasal decongestant, such as furosemide nasal drops, etc., the treatment does not exceed 7 days. Patients who have a runny nose when they are hot should go to the hospital in time, and standardize the treatment after clarifying the cause of the disease.