Wildfire Smoke

Unhealthy levels of wildfire smoke are increasingly affecting Colorado. Wildfire smoke contains harmful particles and chemicals. While conventional advice is to stay inside during wildfire events, smoke can enter buildings, making indoor air unhealthy. 

During wildfire smoke events, air quality can deteriorate quickly and pose serious health risks — especially for children, older adults, and individuals with existing health conditions. It is important to stay informed and take steps to protect your health. Spending time indoors (in homes and other buildings) with clean, well-filtered air, can reduce exposure to smoke and protect your health during a wildfire event.

The Colorado Wildfire Smoke Preparedness Program provides several resources for the general public, but also for schools and educational spaces, and for community and commercial buildings.  For general questions or specific information about the program, email the Colorado Department of Public Health and Environment's indoor air quality team.  

Health Effects from Wildfire Smoke

Health impacts from wildfire smoke depend on many factors, including what’s in the smoke, how long you’re exposed, how much you’re exposed to, and your health history and lifestyle factors.

Breathing in wildfire smoke can:

  • Irritate the eyes, nose, and throat.
  • Cause wheezing, coughing, and difficulty breathing.
  • Worsen asthma, bronchitis, and other lung diseases.
  • Increase the risk of heart attack, heart failure, stroke, and premature death.
  • Affect mental health.

See a health care provider if your symptoms get worse, don’t go away, or disrupt your daily activities.  For medical emergencies, call 911.  

Actions You Can Take

Stay Informed

During wildfire events, conditions can change quickly and may vary neighborhood by neighborhood. Staying informed can help you make choices about your activities to help reduce smoke exposures. Here are some suggestions for staying informed:

Ready Your Home or Other Buildings

  1. Close your doors and windows.
  2. If you have central HVAC, check your HVAC settings and filters:
    • Run the system’s fan as often as possible to keep air circulating through the filters. Choose settings such as “auto” or “fan always on”. This will help trap smoke pollutants that have entered your space, even when you’re not actively heating or cooling the space.
    • Limit the outdoor air intake. Close the dampers or choose the “recirculate” setting on your thermostat. This will reduce the amount of polluted outdoor air being pulled into your space by your HVAC system.
    • Check the condition of your filters to make sure they are clean and well-fitting. To increase efficiency, consider replacing with new filters if it’s been a while since they were last replaces or the filter looks heavily soiled. Install the highest-efficiency filters possible for your system. MERV13+ is best, if it’s available and fits your system’s specifications.
  3. If you do NOT have central HVAC, or you feel you need additional filtration, consider creating a Clean Air Room.
    • Choose a room that is comfortable to stay in for long periods of time and can be closed off from the rest of the house/building. Close windows and doors (including internal doors) to isolate the space and prevent smoke from entering the room.
    • Set up supplemental in-room air filtering, such as portable air cleaners or Do-It-Yourself box fan filters.
    • Stay cool. Run fans or air conditioning to ensure the room doesn’t get too hot. If your home/building uses window-unit ACs, portable ACs with a hose, or evaporative coolers (aka ‘swamp coolers’), keep in mind that these types of units typically pull air in from outside, and do not contain filters that trap smoke. This can bring smoke into your home or building, so the EPA recommends using these devices sparingly during wildfire smoke events.
      • If you do use them, make sure the seals around the unit and the window/wall/door are tight, and use supplemental portable air cleaners or DIY box fan filters in the space to combat the pollution brought in by the unit.
      • If using an evaporative cooler (aka ‘swamp cooler’), if it is safe to access it, you can temporarily completely cover the outside air intakes with 4-inch-thick high-efficiency (MERV 13) furnace filters, which will help trap smoke pollutants and stop them from entering your space. This document has step-by-step instructions on how to do this.
  4. Certain activities in your home/building can create additional smoke or particle pollution.  Based on the wildfire smoke conditions, consider whether you want to hold off certain activities in your home/building, such as:
    • Smoking or vaping
    • Using gas, propane, or wood-burning stoves and furnaces
    • Frying or broiling food
    • Burning candles
    • Spraying aerosol products, like cleaners, air fresheners, hair products
    • Using a vacuum cleaner that does not have a HEPA filter
  5. If you can’t stay cool at home, too much smoke is still entering your home, or the power goes out, staying in a clean room may not be the best option for you. It may be best to seek shelter elsewhere. Consider staying with friends or family, or seeking relief from the smoke in another location with air conditioning and good air filtration.

Protect Yourself Outside

The most effective way to protect yourself from smoke is to stay indoors with cleaner indoor air. For those who must be outside when it is smoky,  reducing the actual time you spend outdoors rather than the intensity of the outdoor activity is more effective in reducing your exposure. If you're in a higher-risk group, reconsider any outdoor activities. Here are additional recommendations:

  • Keep windows and vents closed in your vehicle and set fan/AC to recirculate mode.
  • Drink plenty of water.
  • Check in on animals and pets.  Give them plenty of water and limit activities that will increase their breathing.
  • People who must be outside in smoky air may benefit from wearing a N95 or KN95 mask. Using masks, however, can make it harder to breathe due to the resistance of breathing through them.  Anyone with lung or heart disease should check with their health care provider before using a mask. 

 

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