How to stay safe when wildfires generate unhealthy air quality

March 1, 2024
smoke over fort collins caused by nearby forest fires causes air quality to be unhealthy.
Wildfires cause poor air quality that can be especially dangerous to people with lung and heart problems. Photo: Getty Images.

It is no longer unusual to have smoky air that can mar vistas and make people feel sick during every season.

“Climate change is here to stay. We have rising temperatures and wildfires throughout the year are the new normal,” said Dr. Fernando Holguin, a lung specialist and critical care doctor who runs the severe asthma clinic at UCHealth University of Colorado Hospital.

People with health challenges should be protecting themselves from poor air quality, said Holguin, who is also a professor of pulmonary sciences and critical care at the University of Colorado School of Medicine on the Anschutz Medical Campus.

To help people with lung and cardiovascular health challenges, Holguin outlined the best ways to stay safe from poor air quality related to wildfires.

What’s in smoke and how is it harmful?

“Pollution from fires causes inflammation which narrows passages in our airways. That causes shortness of breath and tightness in the chest,” Holguin said.

Wildfire smoke contains a mix of gases and tiny particles that come from the burning trees, plant material and other things that are fueling the fire.

According to the CDC, wildfire smoke in the air can pose a risk for anyone. Those most at risk include the elderly, pregnant women and people with chronic respiratory and heart conditions. Children are also at a higher risk as they breathe more air per pound of body weight than adults, and wildfire smoke can irritate their still-developing lungs.

Wildfire smoke in the air can sting your eyes and irritate your throat and lungs, resulting in coughing, wheezing, or even an asthma attack or bronchitis. It can cause unexpected symptoms such as chest pain, a rapid heartbeat, headaches, a runny nose and fatigue.

Who is at greatest risk from inhaling smoky air from wildfires?

The short answer is that people who are the youngest, oldest and sickest are most vulnerable to bad outcomes if they breathe air polluted from wildfires. In addition, pregnant women are at high risk if they are exposed to excessive air pollution.

“The risks are most severe for the extremes in ages (children and older adults) and for people with underlying pulmonary diseases,” Holguin said. “Forest fire pollution is very dangerous to cardiovascular patients and people with diabetes, obesity and metabolic problems.”

Read more from experts at the U.S. Centers for Disease Control and Prevention about the dangers of wildfire pollution and how to stay safe.

Do people at high risk get sick immediately after exposure to air pollution?

Dr. Fernando Holguin is an expert on wildfire smoke and the impacts of air pollution on people. He runs a clinic at UCHealth University of Colorado Hospital for people with severe asthma. Photo by Sonya Doctorian, UCHealth.

Sometimes vulnerable people get sick immediately after exposure and visits to hospital ERs can spike on days when monitors detect high pollution levels.

But Holguin’s previous research has found that there is sometimes a lag.

“You get exposed to high levels of air pollution and there’s a lot of inflammation. We see many people coming in for help three days later,” Holguin said.

The timing of dangerous exposure depends on the individual.

“For particulate matter and cardiovascular disease, the day of the exposure is really important,” he said. “For people with respiratory illnesses, there can be a few days lag before symptoms worsen.”

When the air quality is bad, how do people with underlying health conditions know if they need medical help?

“People who have underlying respiratory and cardiovascular disease often wonder if they should see their doctor when air pollution levels are high,” Holguin said.

He gives his patients this key advice: “If you are ever scared, you should seek hep immediately.”

What can people do to protect themselves from wildfire smoke?

“The best way to prevent adverse effects associated with wildfires is to reduce the amount of pollution you’re exposed to,” said Holguin.

When wildfires are bad and air quality is poor, Holguin encourages vulnerable people to protect themselves in the following ways:

  • Follow the news so you know how bad the air quality is. Anyone in the U.S. can get local air quality information from
  • If you are close to an active wildfire, be ready to evacuate. Keep a 7-to-10 day supply of medications on hand along with copies of important documents.
  • If you can see or smell smoke from fires in Colorado or elsewhere in the West, that means air quality is poor.
  • Stay indoors with the windows closed.
  • If you have underlying respiratory or cardiovascular disease, avoid exercising outdoors.
  • Take all of your medications like inhaled medications for asthma.
  • If you have air filters in your home, use them.
  • If you have a swamp cooler (also known as an evaporative cooler), try to avoid running it since it will bring polluted air from the outside into your home.

Why is outdoor exercise on smoky days a concern for people with underlying respiratory or cardiovascular problems?

  • Exercise is normally great for everyone. But on days when air is smoky from wildfires, people are inhaling dirty air with each breath they take. When you exercise vigorously, you breathe more.
  • “Don’t run outdoors when pollution levels are high. You breathe a lot faster and your body is exposed to much higher pollution levels,” Holguin said.

Are smokers at greater risk when wildfires produce dangerous air?

People who smoke are at higher risk for illness all of the time. Poor air quality related to wildfires can exacerbate illnesses that already strike people who smoke in higher numbers.

“Smokers already are putting an incredible amount of air pollution into their lungs. They’re at higher risk already,” Holguin said. “The combustion of tobacco products or anything biological (like marijuana) will generate particulates, carcinogens and volatile organic compounds which can cause a lot of inflammation and long-term damage in the lungs.”

Over the long term, damage from smoking and bad air pollution can increase risk of lung cancer, Holguin said.

Are children at greater risk if they have lung problems and are exposed to consistently high levels of air pollution?

Yes. Studies have found that children who are consistently exposed to high air pollution levels can suffer over the long term because their lungs do not develop to their full capacity. As a result, children can grow into adults with impaired lungs that cannot properly filter air pollution.

Are air purifiers a good idea?

Yes, they are an excellent idea, but it’s important to pick a purifier that actually works.

“Choose wisely,” Holguin said.

The best air purifiers come with HEPA filters, according to experts at the Environmental Protection Agency (EPA). Learn more from EPA pros about how to pick a proper air filter.

And read about how a scientist protects his home when wildfire pollution causes smoky air.

Should I wear a mask to stay safe from wildfires?

The best way to stay safe during smoky days is to stay indoors and to use an air purifier if you have one.

If you need to be outdoors, a tightly-fitting N-95 mask or a P-100 respirator may help filter out some of the harmful particles, according to the National Institute for Occupational Safety and Health.

Masks have also proven highly effective at reducing the spread of the virus that causes COVID-19. So, if you are in crowded indoor spaces, masks can be helpful in reducing the spread of infection.

Is wildfire pollution worse for people who have endured damage to their lungs related to COVID-19?

Researchers don’t fully know how the residual effects of COVID-19 infections affect people. Holguin said there are ongoing studies related to air pollution and COVID-19, and the findings point to a connection that goes both directions.

“In areas where there is air pollution, there are more COVID-19 infections, and the severity of illness may be greater,” Holguin said.

At the same time, some people who became sick with COVID-19 suffered lung damage or may be dealing long COVID and a cough that won’t seem to go away. Like others with lung problems, these people might be more sensitive to smoke from wildfires.

Do more people have sensitive lungs now because of COVID-19?

Researchers still are learning about all of the effects of long COVID and other repercussions from widespread infections during the pandemic. Early research is showing that as many as 30% of people who get COVID-19 may suffer from long COVID. Some of those people have lung problems while others are dealing with neurological challenges like brain fog. (Learn more about Long COVID.)

If a person gets sick when the air is polluted, how can they tell the difference between a COVID-19 infection and illness related to wildfires?

Know the difference between symptoms from smoke exposure and COVID-19.

  • Some symptoms, like dry cough, sore throat, and difficulty breathing can be caused by both wildfire smoke exposure and COVID-19.
  • Learn about symptoms of COVID-19. Symptoms like fever or chills, muscle or body aches, and diarrhea are not related to smoke exposure. If you have any of these symptoms, the CDC COVID-19 Self-Checker can help you determine whether you need further assessment or testing for COVID-19. If you have questions after using the CDC COVID-19 Self-Checker,  contact a healthcare provider.
  • If you have severe symptoms, like difficulty breathing or chest pain, immediately call 911 or the nearest emergency facility.

Holguin encourages vulnerable people to pay close attention to their symptoms and to get tested if they have any doubts.

“The symptoms of COVID-19 and illness from air pollution can be quite similar, including shortness of breath and asthma. However, forest fires don’t cause fever or body aches,” Holguin said. “If you’re ever in doubt, it’s important to get tested for COVID-19 so you can make sure you don’t have the disease and are not spreading it to others.”

Does smoke from fires in other states affect the air quality in Colorado?

It absolutely can, Holguin said.

Depending on wind patterns, polluted air can travel hundreds of miles.

Holguin said Coloradans sometimes suffer a double whammy in the summer. We can get air pollution from local fires while also getting smoky air from fires as far away as California, Oregon and Arizona.

Aside from those who are sick and younger and older people, is anyone else at especially high risk for exposure to fire-related air pollution?

Yes. Holguin said firefighters can deal with extremely dangerous exposures.

“Think of all of the people who have occupational exposure, like land managers and first responders. These people can be exposed to concentrations that are many times higher than potentially life-threatening levels,” Holguin said.

During a wildfire, concentrations of particulate matters (that are about 2.5 microns in diameter) typical hover around 25 micrograms per cubic meter of air volume (or 25 mcg/m3). Learn more about ambient outdoor air quality and how it’s measured from the World Health Organization.

Concentrations of harmful particulates during a fire can be higher than 100 mcg/m3 depending on firefighters’ proximity to a fire.

“That’s high,” Holguin said.

Firefighters and first responders who are in areas with active fires can be exposed to levels in the thousands,” Holguin said.

About the author

Katie Kerwin McCrimmon is a proud Colorado native. She attended Colorado College, thanks to a merit scholarship from the Boettcher Foundation, and worked as a park ranger in Rocky Mountain National Park during summer breaks from college. She is also a storyteller. She loves getting to know UCHealth patients and providers and sharing their inspiring stories.

Katie spent years working as a journalist at the Rocky Mountain News and was a finalist with a team of reporters for the Pulitzer Prize for their coverage of a deadly wildfire in Glenwood Springs in 1994. Katie was the first reporter in the U.S. to track down and interview survivors of the tragic blaze, which left 14 firefighters dead.

She covered an array of beats over the years, including the environment, politics, education and criminal justice. She also loved covering stories in Congress and at the U.S. Supreme Court during a stint as the Rocky’s reporter in Washington, D.C.

Katie then worked as a reporter for an online health news site before joining the UCHealth team in 2017.

Katie and her husband Cyrus, a Pulitzer Prize-winning photographer, have three children. The family loves traveling together anywhere from Glacier National Park to Cuba.