When I started as a respiratory therapist 20 years ago, one of the first observations I made is that people with chronic lung disease, like COPD, do not like heat. They often request fans with the breeze blowing right at their faces. Or, better yet, they request the air conditioning be turned to full blast. Studies seem to support these observations.
A study performed at John Hopkins University showed that COPD patients who were exposed to higher indoor temperatures (such as 90°F) were more likely to have lung function decline, have a flare-up, and require rescue medicine. Those exposed to higher outdoor temperatures were more likely to develop more severe COPD (meaning more severe symptoms).
While the study confirms heat has a negative impact on people with COPD, researchers are not sure of the mechanisms involved. So further studies will surely be performed to figure this out. As more is learned, we’ll be sure to let you know.
What is known is that hotter air has the capacity to absorb and carry more water vapor than colder air. In other words, the hotter the air, the higher the humidity tends to be. That said, hot and humid air is thicker and heavier, and, therefore, harder to inhale. This can make breathing more difficult and uncomfortable.
Worse, humid air tends to harbor fungus, molds and dust mites. For those with allergies, these may cause inflammation of the air passages from the nose all the way to the lungs. This, along with increased secretions, may cause one to feel stuffy.
Previous studies had already linked heat with an increased risk for illness among the very young, overweight, and the elderly population. They also linked heat with increased risk for illness among those with chronic diseases, such as diabetes, heart disease and respiratory diseases, like COPD. Heat also has been linked to increased hospitalizations among these populations.
The John Hopkins study was specifically designed to show the true impact of heat on COPD. Researchers followed 84 former smokers with moderate to severe COPD in Baltimore for 602 days during the summer, in which the subjects reported spending about 48 percent of their time outdoors. High temperatures were considered to be 90°F or higher. The study clearly confirmed that not only is cooler air more comfortable, it may actually have health benefits. This could explain why chronic lung disease patients tend to prefer cooler air.
A similar study was performed back in 1993, and I wrote about it in my post “Can a Simple Breeze Relieve Your Dyspnea?” The study followed patients experiencing dyspnea with normal oxygen levels. Some patients were given 2lpm oxygen continuously, and others were given 2lpm air continuously.
Without knowing whether they had received oxygen or air, both groups noted an 87 percent improvement in perceived dyspnea (feeling like you can’t catch your breath) after three days. So this study may have proven our suspicion that a simple breeze can relieve the feeling of dyspnea.
Most experts already recommend keeping indoor humidity between 35 and 50 percent in order to create a healthy breathing environment. Perhaps these other studies may lead to novel new approaches to treating lung diseases in the future. Of course, one such approach may entail a recommendation of moving to an area where the weather is cooler. For instance, many retired people from Michigan move to Florida during the winter months, only to move back to Michigan during the summer to beat the Florida heat. A better approach may be to recommend fans and air conditioners for anyone with a chronic lung disease to create a breeze and to keep the air cool, refreshing and easy to breathe.
What do you think? Do breezes from fans and open windows make you breathe easier? How about air conditioning? Let us know your thoughts in the comments below.
A Registered Respiratory Therapist and asthmatic