Winter, in the morning, is the “devil’s time” for the onset of acute myocardial infarction, or acute heart attack. This disease is one of the most serious cardiovascular diseases in clinical practice, with high morbidity, mortality, and lethality rates. A careful analysis of the onset of acute myocardial infarction shows two distinctive features: one is that it occurs more often in winter and the other is that it occurs more often in the morning of the day. In fact, scholars have observed the seasonal and hourly pattern of acute heart attack more than 100 years ago. Studies have found that the onset of acute heart attack is related to the time of day, especially in older people over 60 years of age. The incidence was lowest between 5 and 6 a.m.; between 7 and 8 a.m., it was twice as high as between 5 and 6 a.m.; and between 8 and 9 a.m., it was 3.1 times higher than between 5 and 6 a.m. This is basically consistent with American scholars who report that about 40% of acute heart attacks occur in the morning, the “devil’s hour”. The reason for this seasonal and hourly pattern of morbidity is simply a reflection of the unity of heaven and man in the physiological activities of the human body. The cold weather makes the body sympathetic excitement, small blood vessel constriction, blood pressure rise, heart rate speed up, and make the blood fibrinogen increase, fibrinolytic activity decreased and in a high coagulation low solubility state, while making platelet aggregation increased, blood viscosity increased easy to form arterial thrombosis. In the early morning, due to the biological clock effect, as the sun rises, the brain becomes active, sympathetic nerve tension increases, and the concentration of adrenaline, catecholamines and corticosteroids in the blood increases, which will cause the coronary arteries to contract and reduce the blood supply to the myocardium, and also make the heart beat faster and increase the oxygen consumption of the myocardium.