Transient Chest Pain in Summer: A Possible Link to Air Conditioning

Over the past two weeks, two patients contacted me about episodes of transient chest pain. They had undergone various hospital examinations without anything abnormal being found. Because they worried it might be a heart problem, they even had 24-hour Holter monitoring and a coronary CTA, neither of which revealed any abnormality. Yet these results did little to allay their concerns—they still feared sudden cardiac death.

Coincidentally, I recently experienced a similar symptom myself. A few days ago, after sleeping through the night with the air conditioner running, I woke up the next morning with chest pain. I felt somewhat anxious at the time, but I knew my heart and cardiovascular system were fine. Later, I noticed that once I put on a pair of socks and stepped out of the air-conditioned room, the symptoms quickly eased and soon disappeared.

This made me realize that my chest pain might be related to the air conditioning. For those living in cities, going through the midsummer heat without any air conditioning at all is simply unrealistic. Yet many people find it hard to tolerate staying in an air-conditioned room for long.

Air conditioning creates an excessive temperature difference between indoors and outdoors, leaving the blood vessels and the autonomic nervous system insufficient time to adapt, which can give rise to a range of discomforts. When the indoor-outdoor temperature difference exceeds 7–10°C, the autonomic nervous system and vascular regulation cannot keep up. Running the air conditioner requires keeping doors and windows shut, which raises indoor carbon dioxide levels and allows pathogens to accumulate. The cooling process also removes moisture from the air, lowering indoor humidity and weakening the defense of the respiratory mucosa. On top of this, the cold airflow causes a sudden drop in surface body temperature, local vasoconstriction, and muscle spasm. All of these can produce a variety of symptoms.

That said, this problem generally does not require medication. The two patients who consulted me about it had symptoms much like my own: they resolved quickly and did not persist. My own case was the same.

So if you are experiencing something similar, there is no need to be anxious. Still, summer heat leaves the body relatively vulnerable—heatstroke and other mishaps are more likely—and when compounded by the side effects of air conditioning, there is a certain element of danger. During summer, we should therefore avoid excessive exertion and ensure adequate sleep.

When using air conditioning, try not to stay in the air-conditioned room for too long. Depending on your own physical condition, step out of the room briefly every one to two hours, and ventilate the room for 10–15 minutes every one to two hours as well. Install a wind deflector over the air conditioner outlet and use a humidifier indoors. These measures work better than medication.

If symptoms persist without relief, medical attention is warranted. Persistent fever, worsening cough, dyspnea, generalized body pain, chest pain, joint pain, and other symptoms that linger without improvement should prompt a visit to a doctor.
In TCM, when treating externally contracted diseases or pain-related conditions that occur in summer, the air conditioning factor should be taken into account, and the condition should be managed according to the wind-cold pattern. Formulas containing Mahuang (ephedra) and Guizhi (cassia twig) may be used as appropriate, without being bound by the traditional precept that these two herbs should not be used in spring and summer.