The heartbeat is accelerated in hot weather. The body’s metabolic rate increases when the weather is hot, and there will be a lot of sweating, blood vessel expansion and blood circulation accelerated. In order to meet the needs of the body, the heart rate will compensate for the increase, which is a normal phenomenon, but the increase in heart rate will not be too much, generally around 10 times/min. If the heart rate increases significantly, consider whether there is heat stroke or other disease states that cause tachycardia. Common causes of increased heart rate include hyperthyroidism, myocardial ischemia, fever, anemia, etc. If there are obvious symptoms of rapid heartbeat, it is recommended to go to the hospital for electrocardiogram, exercise panel test or 24-hour ambulatory ECG monitoring in order to exclude organic arrhythmia. If there is no organic pathology, it is considered that the reserve capacity of the heart is too poor, and it is recommended to increase physical exercise to lower the basal heart rate.