The American Heart Association is alerting the public that the combination of wildfire smoke drifting from Canada and extreme summer heat poses a potentially deadly threat to heart health, 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 Manesh R. Patel, M.D., FAHA, volunteer president of the American Heart Association. “We want people to be mindful of the increased risk and take steps to protect themselves and their loved ones.”
While respiratory issues are often the primary concern with wildfire smoke, Patel emphasized the serious impact on cardiovascular health. Wildfire smoke contains fine particulate matter linked to cardiovascular risk. A study published in Circulation found that the risk of fatal heart attacks nearly doubled during days of extreme heat and high levels of fine particle pollution, with greater risks for women and older adults.
Research has also linked smoke exposure to increased risk of sudden cardiac arrest and higher emergency room visits for cardiovascular causes. A study in the Journal of the American Heart Association found that heavy wildfire smoke raised the risk of out-of-hospital cardiac arrests by up to 70%, affecting both men and women, adults aged 35-64, and those in lower socioeconomic status communities.
To reduce risks, Patel recommends staying indoors with doors and windows closed, using high-efficiency air filters, limiting outdoor activity during peak heat, wearing masks outdoors, staying hydrated, and avoiding alcohol and caffeine. Checking on older adults and those with chronic conditions is crucial, as is recognizing signs of heart attack or stroke, such as chest discomfort, shortness of breath, and cold sweats. Heat stroke symptoms include body temperature above 103°F, hot red skin, rapid pulse, and confusion.
The U.S. Environmental Protection Agency offers a zip code-level air quality tracking map at airnow.gov. Patel advises checking it regularly and staying informed about local health alerts. “Protect yourself, be alert and prepared,” he said. “It could be the difference in saving your life or that of someone you love.”
