Protecting Yourself From Wildfire Smoke

How to Protect Yourself From Wildfire Smoke

How to Protect Yourself From Wildfire Smoke
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Wildfire smoke is a growing health threat, even for people living thousands of miles from the flames.

”Part of climate change is extreme weather patterns that include more winds that spread smoke more widely,” says Mary Margaret Johnson, MD, PhD, a research scientist with the Harvard T.H. Chan School of Public Health in Boston.

This smoke poses serious risks, especially to some vulnerable groups.

People exposed to wildfire smoke may experience minor issues, such as stinging eyes, scratchy throats, and headaches, as well as more severe reactions like difficulty breathing and heart attacks.

”Wildfires cause particulate matter pollution, which is one of the largest environmental health-risk factors contributing to premature deaths worldwide,” says Rebecca Saari, PhD, an associate professor of civil and environmental engineering and a research chair in global change, atmosphere, and health at the University of Waterloo in Ontario.

In a study, researchers at Stanford University estimated that smoke from wildfires was responsible for the premature deaths of an average of 40,000 Americans yearly between 2011 and 2020 and can cause death up to three years after the initial exposure.

Ways Wildfire Smoke Can Make You Sick

The Centers for Disease Control and Prevention (CDC) notes that even healthy people can feel sick from exposure to air pollutants caused by wildfires. Breathing in wildfire smoke quality can cause:

  • Headache
  • Irritated eyes and sinuses
  • Runny nose
  • Coughing or scratchy throat
  • Fatigue
  • Chest tightness

”If you feel extreme shortness of breath or chest pain that’s concerning, you will want to get to an emergency room or call 911,” says Timothy Daum, MD, a pulmonologist with University of Michigan Health–West, based in Wyoming, Michigan.

Who Is at Highest Risk From Wildfire Smoke?

The Environmental Protection Agency (EPA) warns that adults over 65, children (whose lungs are still developing), and pregnant individuals are most susceptible to wildfire smoke.

Those who already have underlying lung issues — such as chronic obstructive pulmonary disease (COPD), asthma, and bronchitis — face a higher risk of breathing difficulties. ”Smoke adds insult to already-injured lungs,” says Purvi Parikh, MD, an allergist and immunologist with NYU Langone Health in New York City and a medical adviser for the Allergy and Asthma Network.

As Dr. Daum stresses, pollutants caused by wildfire smoke can also aggravate chronic cardiovascular issues. People with heart disease should be on the alert for signs of heart attack, stroke, and arrhythmia (irregular heartbeat). Researchers estimate that exposure to wildfire smoke may cause about 17,000 strokes in the United States.

 And repeated or long-term exposure can increase the risk of heart failure for older adults, women, and economically vulnerable people, according to a study that analyzed 22 million Medicare enrollees.

”When this small particulate matter gets into a person, it sets up inflammation and adverse consequences throughout the body,” says Daum.

Air pollution can also throw off your immune system, making you more susceptible to any type of respiratory virus, including the flu, RSV, and COVID-19. Research from Harvard University found that even a slight rise in particulate matter in the air was linked with a 15-percent increase in the COVID-19 death rate.

While the long-term effects of wildfire smoke are not certain, emerging research has linked wildfire smoke exposure to a significant increase in the risk of lung cancer, colorectal cancer, breast cancer, bladder cancer, and blood cancer. Higher concentrations of smoke may further increase these risks, although more study is needed.

”Damage to heart, vasculature, and lungs can be permanent, and it can be fatal,” says Otis Brawley, MD, a professor of oncology and epidemiology at Johns Hopkins University in Baltimore.

Why Wildfire Smoke Is So Dangerous

While all the pollutants that wildfire smoke releases can harm your health, fine particles from wildfire smoke pose the biggest threat.

These particles are measured as PM2.5, atmospheric particulate matter that has a diameter of less than 2.5 micrometers.

These minute pollutants, which are just 3 percent of the diameter of a human hair, are particularly hazardous. The body can filter out many coarser particles, but PM2.5 can penetrate deep into the lungs and impair their function.

The EPA considers it safe to breathe PM2.5 levels that don’t go over a concentration of 35 micrograms per cubic meter of air (mcg/m3) within a day, as long as the yearly daily average comes out to 9 mcg/m3 or less.

Dr. Johnson cautions that it doesn’t take much of a rise in PM2.5 to ignite health problems. ”With just a 10-unit increase in PM2.5, you’ll see an uptick in emergency room visits and hospital admissions for heart attacks, strokes, arrhythmias, and severe breathing problems related to asthma, COPD, or bronchitis,” she says.

”When the level reaches 200, it’s like smoking almost 9 or 10 cigarettes a day, and that’s for everyone — babies and older people included,” she adds.

How to Protect Yourself From Wildfire Smoke

When air quality veers into the danger zone, take these steps to protect yourself:

Avoid Going Outside One of the easiest actions to minimize breathing in smoky air is to stay indoors. The CDC instructs people to keep windows and doors shut and run an air conditioner, keeping the AC’s fresh-air intake closed and the filter clean to prevent outdoor smoke from getting inside. Those without air-conditioning may want to seek out an air-conditioned community center.

If you do want to go outside during a period when wildfire smoke is high, Johnson suggests that conditions may be somewhat better at night or early in the morning or later in the day when there is less sunlight.

”When you don’t have sunlight, you’re going to have less conversion of pollutants to ozone [which is highly dangerous to a person’s health],” she says.

Daum adds, however, that there is no reliable time of day that is better than any other when it comes to air quality.

Check the Air Quality Index (AQI) ”Fortunately, most smartphones provide a measure of air quality under their weather apps,” Daum says. ”This can be a reliable guide as to when it is safe to exercise or work outdoors.” You can also check at the EPA’s AirNow website. These resources measure the air quality by taking into account current levels of major pollutants, including ground-level particulate matter, carbon monoxide, ozone, and sulfur dioxide.

Those calculations are translated into an air quality index (AQI), a number ranging between 0 and 500. A level between 0 and 50 poses no health dangers. Members of vulnerable groups may begin having air pollution–related symptoms starting at 51. At 100, the air outside is considered unsafe for them. Most people will start to have noticeable symptoms at a level above 150, and anything above 300 is considered hazardous.

Keep Exercise Indoors and to a Minimum Physical activity increases breathing and heart rates, so when air quality levels go into the red, exercise inside and at a moderate (rather than high-intensity) pace. ”Overexertion should be avoided,” says Dr. Brawley.

Wear an N95 Mask Daum advises wearing an N95 mask that fits snugly around the nose and mouth if you’re outdoors for a long time. ”A regular cloth mask or regular surgical mask probably won’t do much. An N95 probably won’t filter out everything, but it will help.”

Consider Using an Air Purifier Tests by Consumer Reports of air purifiers with HEPA filters show that they can help get rid of harmful particulates. The best air purifiers can reduce particle concentrations by as much as 85 percent. They range in price from $50 to more than $1,000.

The Takeaway

  • Wildfires can worsen air quality and increase the risk of both minor ailments and serious events like heart attacks.
  • This is due to microscopic particulate matter in the smoke, which can get into the lungs and lead to damaging inflammation.
  • Checking the Air Quality Index (AQI) on weather apps or from the EPA can give you an idea of whether it’s safe to go outside during wildfire season.
EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
  1. Qiu M et al. Wildfire Smoke Exposure and Mortality Burden in the USA Under Climate Change. Nature. November 27, 2025.
  2. How Wildfire Smoke Affects Your Body. Centers for Disease Control and Prevention. April 19, 2024.
  3. Who Is at Increased Risk of Health Effects From Wildfire Smoke Exposure? Environmental Protection Agency. October 10, 2025.
  4. Hao H et al. Long-Term Exposure to Wildfire Smoke Particulate Matter and Incident Stroke: A US Nationwide Study. European Heart Journal. January 27, 2026.
  5. Hao H et al. Long-Term Wildfire Smoke Exposure and Increased Risk of Heart Failure in Older Adults. Journal of the American College of Cardiology. July 1, 2025.
  6. Zhou X et al. Excess of COVID-19 Cases and Deaths Due to Fine Particulate Matter Exposure During the 2020 Wildfires in the United States. Science Advances. August 13, 2021.
  7. Exposure to Wildfire Smoke May Be Linked to Increased Risk of Developing Several Cancers. American Association for Cancer Research. April 21, 2026.
  8. Wildfire Smoke and Health. Colorado Department of Public Health and Environment.
  9. Nazarenko Y et al. Air Quality Standards and WHO’s Guidance on Particulate Matter Measuring 2.5 μm (PM2.5). Bulletin of the World Health Organization. January 1, 2025.
  10. NAAQS Table. Environmental Protection Agency. November 4, 2025.
  11. Ozone. American Lung Association. June 9, 2025.
  12. Air Quality Index (AQI) Basics. AirNow.
  13. Christian TA et al. 5 Best Air Purifiers for Wildfire Smoke, According to Our Testing. Consumer Reports. March 13, 2026.
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Jon E. Stahlman, MD

Medical Reviewer

Jon E. Stahlman, MD, has been a practicing allergist for more than 25 years. He is currently the section chief of allergy and immunology at Children’s Healthcare of Atlanta's Scott...

Don Rauf

Author

Don Rauf has been a freelance health writer for over 12 years and his writing has been featured in HealthDay, CBS News, WebMD, U.S. News & World Report, Mental Floss, United Press ...