Feeling chest tightness and shortness of breath in hot weather may be caused by physiological reaction or some kind of cardiovascular or respiratory diseases. 1. Physiological reaction: in hot weather, there may be transient hypoxia, such as not improving the environment will cause chest tightness, shortness of breath. This is a normal behavior and generally does not require special treatment. 2. Cardiovascular diseases: for example, pericarditis, myocarditis and coronary atherosclerosis may cause chest tightness and shortness of breath, which are mainly related to myocardial ischemia and hypoxia. 3. Respiratory diseases: for example, bronchitis, bronchial asthma, pneumonia, etc., may lead to chest tightness and shortness of breath, affecting normal breathing, and related to respiratory obstruction. When the weather is hot, if you feel chest tightness and shortness of breath, you can observe first; if the symptoms cannot disappear after changing the environment, it is recommended to consult a doctor in time.