A cold breath in the chest may be a normal physiological phenomenon, or it may be an adverse symptom caused by coronary heart disease, intercostal neuritis and other diseases, it is recommended to consult a doctor for relevant examinations in a timely manner. 1. Physiological phenomenon: when the ambient temperature is low, it may trigger a cool breath in the chest, and may also cause coldness, which usually does not lead to other discomforts, and is a normal physiological reaction, which will be improved by improving the ambient temperature or adding clothes in time. 2. Coronary heart disease: a cool air in the chest may be a symptom caused by coronary heart disease, the patient will also have palpitations (rapid heartbeat, often accompanied by panic), chest tightness and shortness of breath, limb weakness and other undesirable symptoms, the pain around the chest may be accompanied by angina pectoris in some patients, the onset of the disease may cause dizziness or shock. 3. Intercostal neuritis: suffering from intercostal neuritis may also cause such discomfort, suffering from such diseases may lead to chest cold, tingling sensation and other undesirable symptoms, the patient is subjected to wind or cold, will make the disease more intense, sneezing or violent coughing when the pain will be aggravated. There are other causes of a cold breath in the chest, you need to go to the hospital in time, diagnose the cause of the disease, under the guidance of the doctor’s advice and active treatment, to avoid further development of the condition.