The American Heart Association is raising alarms about the compounded health risks posed by wildfire smoke drifting from Canadian fires and record-breaking summer temperatures across parts of the United States. According to the organization, the combination of extreme heat and air pollution from wildfire smoke creates a potentially deadly situation, particularly for individuals with chronic conditions such as heart disease.
“Extreme heat and wildfire smoke each carry major risks, especially for people with chronic health conditions including heart disease. The combination of the two is extremely dangerous,” said Dr. Manesh R. Patel, volunteer president of the American Heart Association and a cardiologist at Duke University School of Medicine. He emphasized that while respiratory issues are commonly associated with wildfire smoke, the cardiovascular impact is equally serious and far-reaching.
Wildfire smoke contains fine particulate matter (PM2.5) that can enter the bloodstream and trigger cardiovascular events. A study published in Circulation, the American Heart Association’s flagship journal, found that the risk of fatal heart attacks nearly doubled during days of extreme heat combined with high levels of fine particle pollution. The risks were even greater for women and older adults.
Research has also linked smoke exposure to increased rates of sudden cardiac arrest. A study in the Journal of the American Heart Association found that heavy smoke during wildfires raised the risk of out-of-hospital cardiac arrests by up to 70%. Elevated risks were observed across genders, among adults aged 35–64, and in communities with lower socioeconomic status. Previous findings from the same group noted increased emergency room visits for ischemic heart disease, arrhythmias, heart failure, pulmonary embolism, and stroke.
Dr. Patel offered several tips to reduce exposure and protect heart health during this dual threat. He recommends staying indoors with doors and windows closed, using high-efficiency air filters in air conditioning systems or portable air cleaners, which can reduce indoor particulate matter by 50–60% according to the American Heart Association’s 2020 scientific statement on air pollution. If homes lack air conditioning, seeking alternative shelter is advised. Outdoor activity should be limited, especially between noon and 3 p.m., and masks should be worn outdoors.
For those who must be outside, Patel advises avoiding exertion, taking breaks in shade or cool indoor spaces, and staying hydrated with water while avoiding alcohol and caffeine. Lightweight, light-colored clothing, hats, and sunscreen are recommended. Checking on older adults and those with chronic conditions is crucial, as they face higher risks. Pets should also be brought indoors.
Recognizing signs of a heart attack or stroke is critical. Symptoms include chest discomfort, discomfort in the upper body, shortness of breath, cold sweat, nausea, or lightheadedness. Heat stroke, a separate emergency, presents with body temperature above 103°F, hot red skin, rapid pulse, confusion, or loss of consciousness. In any emergency, call 911 immediately. Knowing and performing CPR can more than double survival chances for cardiac arrest.
The U.S. Environmental Protection Agency offers a zip code-level air quality tracking map at airnow.gov, which Patel recommends checking regularly. Staying informed about local health alerts is also important. “Protect yourself, be alert and prepared,” Patel said. “It could be the difference in saving your life or that of someone you love.”
