If you’re already coughing, wheezing, or short of breath right now
Stop reading and get help first. Severe shortness of breath, chest pain, lips or face turning bluish, or confusion during a smoke event are emergency signs — call 911 or your local emergency number. If you have asthma, COPD, or heart disease and your symptoms are worse than usual and not relieved by your regular medicine, contact your healthcare provider or seek urgent care right away. The rest of this guide is for planning ahead, not for managing an emergency in progress.
What should you do about wildfire smoke and indoor air?
When wildfire smoke is near you, check current air quality on AirNow’s Fire and Smoke Map, close windows and set up a “clean air room” with a portable air cleaner or a high-efficiency HVAC filter, and wear an N95 respirator — not a cloth mask — for any essential outdoor time. This guide walks through the reasoning and sourcing behind each of those steps.
Who faces higher risk from wildfire smoke?
Most healthy adults and children experience only mild, short-lived symptoms from wildfire smoke and recover quickly. AirNow identifies several groups more likely to experience serious health effects: people with lung disease such as asthma or COPD, people with heart disease, children and teenagers, older adults (generally 65 and up), pregnant women, and people who are more likely to be exposed outdoors, such as outdoor workers.
If you fall into one of these groups, the practical takeaway is: plan before smoke arrives rather than deciding in the moment. If you don’t fall into a higher-risk group, you still benefit from checking air quality and reducing strenuous outdoor activity on smoky days, since even healthy people can experience temporary respiratory irritation.
A short process map: before, during, and after smoke
- Before a smoke event: Identify a clean air room, stock several days of any regular medicines and food that doesn’t require cooking, line up a portable air cleaner or an HVAC filter rated MERV-13 or higher if your system can safely use one, and talk with your healthcare provider about your personal risk plan.
- During a smoke event: Check current air quality before going outside, limit or reschedule strenuous outdoor activity, close windows and doors, run your clean air room setup, and avoid indoor activities that add pollution, such as frying food, vacuuming, or using gas or wood-burning appliances.
- After a smoke event: Continue checking air quality until it returns to healthy levels, since smoke can linger after a visible fire has passed, and take precautions before cleaning up any ash.
How do you check whether today’s air is actually a problem?
AirNow’s Fire and Smoke Map shows current particle pollution (PM2.5) levels — the pollutant of greatest concern in wildfire smoke — along with the Air Quality Index (AQI) for your area.
Smoke levels can shift significantly within a single day, so it’s worth checking again before an outdoor activity rather than relying on a reading from that morning. Many state, local, and tribal air quality agencies also offer email or text alerts you can sign up for in advance, so you’re not checking manually every hour during a smoke event.
Do you need a respirator, and which kind actually helps?
Cloth masks do not protect against wildfire smoke, according to AirNow. An N95 respirator mask is the option identified as offering protection from smoke particles.
If outdoor work can’t be rescheduled to a lower-smoke period, official guidance recommends limiting time outdoors to essential activities, taking frequent breaks in clean indoor air, and wearing an N95 respirator while working outside. Some areas have specific regulations for outdoor workers during smoke events, so it’s worth checking local rules if this applies to you.
What does a “clean air room” mean, and how do you set one up?
A clean air room is a single space in your home — often a bedroom or living room — set up to keep smoke out and filtered air in. Everyone can benefit from one during a wildfire, but it’s most helpful for people at greater risk.
AirNow’s guidance describes running a portable air cleaner continuously on its highest effective fan speed, choosing a unit sized appropriately for the room, and avoiding ozone-generating air cleaners. If you have central air conditioning, using it with a high-efficiency filter (MERV-13 or higher, if your system can safely handle one) and setting it to “Recirculate” and “On” rather than “Auto” can help filter air throughout the home. Closing any fresh-air intake on the system during heavy smoke is also part of this guidance.
What if you can’t get a portable air cleaner in time?
Official guidance describes a do-it-yourself option built from a box fan and a filter as a fallback when a commercial portable air cleaner isn’t available.
The guidance specifically cautions that the fan should be a newer model (2012 or later), since older box fans may pose an electrical or fire hazard, and that a DIY unit should never be left unattended, including overnight.
What should you avoid doing indoors during a smoke event?
Frying food, sweeping, vacuuming, and using gas, propane, or wood-burning stoves and furnaces all add pollution to indoor air at exactly the time you’re trying to keep it clean. If you need to cook, options that don’t require heat or a long cook time reduce this problem.
What should you do after the smoke clears?
Smoke and ash can linger after a fire is out, so continue checking air quality rather than assuming conditions are back to normal once you stop seeing visible smoke.
If ash has settled indoors or outdoors, AirNow’s guidance recommends avoiding stirring it up: mist ash with water before sweeping, use damp cloths or a HEPA-type vacuum, and clean surfaces, carpets, and bedding with water and mild detergent. Replace filters in your HVAC system or portable air cleaner, and continue filtering until the smoke odor fades. AirNow also notes that anxiety, trouble sleeping, and other stress reactions are common responses to wildfires, and that support is available around the clock through the Disaster Distress Helpline at 1-800-985-5990 for anyone who notices these symptoms persisting.
A prepare-now checklist
- Pick a clean air room and identify how you’ll seal it (close windows and doors, close any fresh-air HVAC intake)
- Have several days of any regular medicines on hand
- Stock groceries that don’t need refrigeration or cooking
- Have N95 respirator masks available for essential outdoor time
- Have a portable air cleaner or, at minimum, a newer box fan (2012 or later) and a filter for a DIY setup
- Check whether your HVAC system can safely use a MERV-13 or higher filter, and have a replacement on hand
- Bookmark the AirNow Fire and Smoke Map and sign up for local air quality alerts
- Talk with your healthcare provider in advance if you have asthma, COPD, heart disease, or are pregnant, older, or caring for children
- Write down where you and your pets would go if evacuation becomes necessary
Frequently asked questions
Is it ever safe to exercise outdoors during a smoke event?
Official guidance is to take it easy when smoke is in the air—limiting or lowering the intensity of outdoor exercise reduces how much smoke you inhale. The recommended approach is to check current air quality before heading out and wait for better conditions when possible, rather than relying on a fixed cutoff.
Can an ordinary furnace filter replace a MERV-13 filter during smoke events?
Guidance recommends a high-efficiency filter rated MERV-13 or higher for filtering smoke, used only if your HVAC system can safely handle that rating—check your system’s specifications or ask an HVAC professional before upgrading the filter.
Should children or people with asthma help clean up ash after a fire?
Guidance recommends misting ash with water before sweeping and using a HEPA-type vacuum and damp cloths to limit airborne particles during cleanup, and wearing an N95 respirator during the work. If you or a household member is in a higher-risk group, have someone else handle the cleanup when possible.
How long can wildfire smoke affect air quality after the fire itself is out?
Smoke can linger in an area for days after a wildfire ends, so continuing to check the AirNow Fire and Smoke Map after visible fire activity stops — rather than assuming air quality has returned to normal — is the recommended approach.
Where can I get help if wildfire smoke season is causing ongoing anxiety or stress?
The Disaster Distress Helpline (1-800-985-5990) provides free, 24/7 support and counseling for anxiety, sleep trouble, and other stress reactions connected to disasters, including wildfires.
Related reading on this site
If you’re managing COPD or another chronic respiratory condition, our COPD & Respiratory Wellness section covers general terminology and questions worth raising with a pulmonologist or primary care provider. This article was built following the verification process described on our How We Review page, and you can read more about our editorial identity on our About page.
Sources
- AirNow.gov — Wildfires (including the linked Be Smoke Ready, When Smoke is in the Air, and After a Fire pages), a joint resource of the EPA and partner agencies
- U.S. Environmental Protection Agency — Prepare for Wildfire Smoke
Medical disclaimer: This article provides general educational information only. It is not medical advice, does not diagnose or treat any condition, and is not a substitute for guidance from a licensed healthcare provider. If you are experiencing severe shortness of breath, chest pain, or coughing up blood, seek emergency care.
By SmokersLung.com Respiratory Health Education Team. Last updated: September 2026.