High temperature itself has little effect on the heart of normal people. High temperature most of all causes changes in systemic thermoregulation, which causes neuroendocrine secretion disorders and leads to sympathetic excitation, which may lead to other problems. If high temperatures lead to sympathetic excitation, normal people may not be affected, but if patients with underlying heart disease, it may lead to catastrophic results, such as high temperatures with previous coronary heart disease, angina, a history of heart attack or previous heart failure symptoms. Sympathetic excitement at high temperatures can suddenly lead to heart attacks, especially when the climate changes, when low temperatures turn into heat, or when the heat suddenly turns to cold, which can cause cardiovascular disease and lead to heart attacks and brain attacks. If the patient has heart failure in the past, the high temperature may lead to low air pressure, the heart failure patient lack of oxygen, and in the high temperature state, sympathetic excitement, resulting in increased burden on heart function, heart failure further extension, causing a series of symptoms of cardiac insufficiency.