Caused by the heat of the day chest congestion, the reasons are mainly environmental confinement, heat stroke and coronary heart disease. 1. Environmental confinement: when the day is hot, it can lead to sympathetic nerve excitation, the body’s oxygen demand will increase, if this is in a closed environment, air circulation, oxygen is not enough, may appear hot chest congestion. 2. Heatstroke: Heatstroke is a disease in which the temperature or humidity in the environment is too high, leading to dysfunction of the thermoregulatory center or sweat glands. Due to the large loss of water and electrolytes, the body’s internal balance is disturbed, can appear chest tightness, dizziness, excessive sweating, and even fainting and other symptoms. 3. Coronary heart disease: Coronary heart disease is a cardiovascular disease in which the coronary arteries supplying blood to the heart are narrowed, resulting in insufficient blood and oxygen supply to the heart. The heat of the day will lead to an increase in myocardial oxygen consumption, due to coronary heart disease can not provide sufficient oxygen to the myocardium, so there will be chest congestion. Chest congestion in hot weather may also be caused by other reasons, such as a long time can not be relieved or the symptoms gradually increase the importance of timely access to hospitals to receive professional medical treatment, do not delay.