The American Heart Association is alerting the public to the heightened cardiovascular dangers posed by the convergence of wildfire smoke and extreme summer heat, which is affecting large parts of the United States as smoke from Canadian wildfires drifts southward while temperatures soar.
“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. He emphasized that beyond the immediate dangers of fires, the health impacts extend far beyond respiratory issues.
Wildfire smoke contains fine particulate matter linked to cardiovascular risk. 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 and high levels of fine particle pollution. Other research has linked smoke exposure to increased risks of sudden cardiac arrest and higher emergency room visits for cardiovascular conditions. A study in the Journal of the American Heart Association reported that heavy wildfire smoke raised the risk of out-of-hospital cardiac arrests by up to 70%, with elevated risks across genders and age groups.
To reduce exposure, the American Heart Association recommends staying indoors with doors and windows closed, using high-efficiency air filters or portable air cleaners, which can reduce indoor particulate matter by 50-60%. Limiting outdoor activity, especially between noon and 3 p.m., is advised. If going outside, wearing a mask, avoiding exertion, and staying hydrated with water—avoiding alcohol and caffeine—are crucial. Lightweight, light-colored clothing and sunscreen are recommended for heat protection.
Patel stressed checking on older adults and those with chronic conditions, as they face higher risks. Pets should also be brought indoors. Recognizing signs of heart attack or stroke—such as chest discomfort, shortness of breath, or nausea—and calling 911 immediately is vital. For heat stroke, symptoms include body temperature above 103°F, rapid pulse, and confusion. The American Heart Association also highlights that knowing CPR can double the chance of survival in cardiac arrest.
Real-time air quality information is available at airnow.gov, and local health department alerts should be monitored. “Protect yourself, be alert and prepared,” Patel said. “It could be the difference in saving your life or that of someone you love.”
