The American Heart Association is alerting the public that the convergence of wildfire smoke drifting from Canada and record-breaking summer temperatures across parts of the United States creates a potentially deadly situation for heart health. The organization emphasizes that while respiratory issues are often the primary concern with wildfire smoke, the cardiovascular impact is equally serious and far-reaching.
"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 Manesh R. Patel, M.D., FAHA, volunteer president of the American Heart Association and chief of the division of cardiology at Duke University School of Medicine. "We want people to be mindful of the increased risk and take steps to protect themselves and their loved ones."
Dr. Patel explained that wildfire smoke contains fine particulate matter that can enter the bloodstream and trigger cardiovascular events. A study published in Circulation, the flagship journal of the American Heart Association, found that the risk of fatal heart attacks nearly doubled during days of extreme heat and high levels of fine particle pollution. The risks were even greater for women and older individuals.
Additional research published in the Journal of the American Heart Association found that exposure to heavy smoke during wildfires raised the risk of out-of-hospital cardiac arrests by up to 70%. The risk was elevated among men and women, adults aged 35-64, and communities with lower socioeconomic status. Other studies have linked smoke exposure to increased emergency room visits for ischemic heart disease, irregular heart rhythm, heart failure, pulmonary embolism, and stroke.
To reduce risks, the American Heart Association recommends staying indoors with doors and windows closed, using high-efficiency air filters, and limiting outdoor activity, especially between noon and 3 p.m. when temperatures peak. If outdoor activity is necessary, wearing a mask, avoiding exertion, staying hydrated with water, and wearing lightweight, light-colored clothing are advised. It is also important to check on older individuals and those with chronic conditions, as they are at higher risk.
Recognizing the signs of a heart attack or stroke is critical. Symptoms may include chest discomfort, discomfort in other upper body areas, shortness of breath, cold sweat, nausea, lightheadedness, or an irregular heartbeat. For heat stroke, symptoms include a body temperature above 103°F, hot red skin, rapid pulse, confusion, or loss of consciousness. In either case, calling 911 immediately is essential.
Dr. Patel also highlighted the importance of knowing CPR, which can more than double the chance of survival in cardiac arrest. The U.S. Environmental Protection Agency offers a zip code-level tracking map of current air quality at airnow.gov. The American Heart Association provides additional resources at heart.org. "Protect yourself, be alert and prepared," Patel said. "It could be the difference in saving your life or that of someone you love."
