Breathing heavy wildfire smoke can:

• Increase your risk of heart attack
• Trigger irregular heart rhythms 
• Increase your risk of stroke
• Aggravate existing heart conditions

Who should take extra care during a smoke event:

• Adults over 65
• Everyone with heart disease, a cardiovascular condition, or high blood pressure
• Everyone with diabetes
• Pregnant people

Protect your heart on smoky days.

When the Air Quality Index (AQI) is above 100:

• Limit strenuous outdoor activity
• Spend time in a “Cleaner Air” space
• Stay hydrated
• Follow your healthcare provider's recommendations

How does wildfire smoke impact your heart health? 

Wildfire smoke contains microscopic particles that are small enough to travel deep into your lungs and enter your bloodstream. These particles can trigger inflammation throughout your body, placing additional stress on the heart and blood vessels.

Smoke-related inflammation can:

• Make your heart work harder
• Raise your blood pressure
• Increase strain on the cardiovascular system
• Increase your risk of blood clots

Breathing wildfire smoke can have short and long-term health impacts. 

Short-term risks: 

• Breathing in heavy wildfire smoke increases the chance of cardiac arrests by up to 70%.
• Studies of emergency room visits show a 42% spike in admitted heart attacks and a 22% increase in visits for heart disease within a day of an extreme smoke event. (1)

Long-term risks: 

• Research published by the American College of Cardiology links long-term wildfire smoke exposure to an increased risk of heart failure. (2)
• A nationwide study found that long-term wildfire smoke exposure increases the risk of stroke among adults age 65 and older.(3)

References:

1. Jones CG, Rappold AG, Vargo J, et al. (2020) Out-of-Hospital Cardiac Arrests and Wildfire-Related Particulate Matter During 2015-2017 California Wildfires. J Am Heart Assoc. 
2. Wettstein ZS, Hoshiko S, Fahimi J, et al. (2018) Cardiovascular and Cerebrovascular Emergency Department Visits Associated With Wildfire Smoke Exposure in California in 2015. J Am Heart Assoc. 
3. Hao H, Xu K, Zhang D, et al. (2025). Long-Term Wildfire Smoke Exposure and Increased Risk of Heart Failure in Older Adults. Journal of the American College of Cardiology. 
4. Hao H, Xu K, Zhang D, et al. (2026). Long-term exposure to wildfire smoke particulate matter and incident stroke: a US nationwide study. European Heart Journal.