When smoke rolls in, the air inside your home matters
Wildfire smoke travels hundreds of kilometres and worsens the air far from the flames. Here is how to recognise the symptoms, what to do, and how to protect the people you love.
Wildfire smoke does not stay where the flames are. It travels hundreds of kilometres on the wind, crosses regions and borders, and can worsen the air you breathe far from the fire itself. In recent years this was clear with the large fires in Canada and the northern United States, whose smoke reached very distant areas, as far as Europe; and the same happens every summer during the wildfire season across the Mediterranean basin.
What surprises many people: you do not have to see haze to be breathing it. Fine particles and gases can be so diluted that the sky looks clear or only slightly hazy, while ground-level air quality has already deteriorated. Conversely, sometimes the sky is hazy and sunsets turn red because smoke is passing at high altitude, with little effect on the air you breathe. The reliable way to know is not your eyes but the data (see below how to check the air quality index).
Want to understand what smoke contains and how it acts on the body? Read our in-depth article Wildfires and air quality: health risks and indoor protection.
What is really in wildfire smoke (and why it is dangerous)
Wildfire smoke is not just soot. It is a mix of fine particulate matter (PM2.5), particles small enough to reach deep into the lungs and the bloodstream, plus gases and chemicals released when vegetation, buildings, vehicles and materials burn. That is why smoke can cause headaches, a scratchy throat, chest tightness or unusual fatigue, sometimes before you even notice the smell.
The practical takeaway matters: protecting yourself takes two different actions, not one.
Fine particles (PM2.5)
Microscopic, they slip past the body's natural defences and reach deep into the lungs. A medical-grade HEPA filter is what captures them.
Gases and chemicals
Released as things burn. Particle-only filters miss them: it takes activated carbon to adsorb them.
Symptoms of smoke exposure
Smoke affects people differently, and some signs are easy to mistake for a cold, an allergy or plain tiredness. Watch how you and your family feel during smoky days, especially anyone with asthma, allergies, COPD or a heart condition: they tend to feel it first and most strongly.
Common and mild
- Coughing, a scratchy or sore throat
- Watery, itchy or burning eyes
- Runny or stuffy nose, sinus pressure
- Headache, sneezing, congestion
- Unusual tiredness or "brain fog", even without smelling smoke
More serious
- Shortness of breath or difficulty breathing
- Wheezing or a persistent, worsening cough
- Chest tightness or chest pain
- Heart palpitations or a racing heartbeat
- Dizziness or lightheadedness
- A clear flare-up of asthma or COPD
When to seek help: trouble breathing, chest pain or pressure, a rapid or irregular heartbeat, confusion or severe dizziness are not "wait and see" symptoms. If they appear, especially in someone with a heart or lung condition, a young child, an older adult or a pregnant person, contact a doctor promptly. In an emergency, call your local emergency number (112 in the EU).
A good rule of thumb: if your symptoms line up with the smoky days and ease when the air clears, wildfire smoke is very likely the cause, and it is worth reducing your exposure. An air purifier and a "clean room" support cleaner indoor air, but they are not a substitute for medical care.
What to do (and what to avoid) while the smoke lingers
Do
✓ Stay indoors until the air improves: your home is your best shield. Postpone errands and outdoor chores.
✓ Keep windows and doors closed and run any AC on recirculate.
✓ Use fans and AC to stay cool, without trading clean air for cool air by opening windows.
✓ Run a HEPA + activated carbon purifier continuously and set up a clean room to sleep in.
✓ Check on vulnerable people (asthma, COPD, heart conditions, older adults, young children, pregnancy).
✓ Keep medications on hand and already filled.
✓ Check the air quality index daily: the European Air Quality Index (EEA) or your local authority.
✓ If you go out, wear a fitted FFP2 (or N95) respirator and keep outings short.
✓ Stay hydrated and rest: it supports your body's natural defences.
Don't
✗ Don't exercise outside in poor air: you breathe harder and pull more smoke into your lungs.
✗ Don't open the windows, even at night: it undoes every other effort.
✗ Don't let kids play outside when it is hazy.
✗ Don't sweep or dry-vacuum ash: it kicks particles back into the air. Damp-wipe instead.
✗ Don't rely on DIY purifiers: not sealed and useless against gases.
✗ Don't rely on cloth or surgical masks: they do not filter fine particles.
✗ Don't add indoor air pollution: no candles, incense, frying, fireplace, smoking or vaping indoors.
✗ Don't rely on the colour of the sky alone: diluted smoke may be invisible. Watch the index numbers.
✗ Don't ignore serious symptoms: in an emergency call 112.
The one thing that matters most: HEPA and activated carbon
A quality air purifier is the single most effective thing you can do for your indoor air during wildfire smoke. Smoke is particles and chemistry together: so you need HEPA to capture the fine particles and activated carbon to adsorb the gases. Particle-only filters leave the chemistry behind.
Run it continuously and consider creating a clean room, often a bedroom, where the whole family can rest and sleep in the cleanest air in the house. Austin Air purifiers combine medical-grade HEPA (99.97% of particles at 0.3 microns) with activated carbon and zeolite, are handmade in the USA and backed, for consumers, by a 3-year warranty on mechanical and electrical components, with filters lasting up to 5 years.
HealthMate Plus
Focused on smoke and chemical odors
Medical-grade HEPA plus activated carbon and zeolite, with potassium iodide-impregnated carbon (up to 6.8 kg), designed to better handle smoke, formaldehyde, ammonia, VOCs and the chemical odors typical of wildfire smoke.
Explore HealthMate PlusImmunity Machine
8-stage, the most complete protection
Two prefilters, medical-grade HEPA, a four-part granular system (carbon and zeolite, some impregnated) and military-grade HEGA Cloth against gases and chemicals: the maximum for the most exposed spaces.
Explore Immunity MachineNot sure which model is right for you? Get in touch and we will help you choose.
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WhatsAppHow to protect your home: the 5-step plan
You cannot control the fires or the wind, but you can control the air inside your home.
- Seal doors and windows.
- Filter the air with HEPA and activated carbon, continuously.
- Set up a clean room to rest and sleep in.
- Check on the vulnerable.
- Follow your local air quality index every day.
Frequently asked questions
How far can wildfire smoke travel?
Hundreds, sometimes thousands, of kilometres from the fire. Carried by prevailing winds, it regularly crosses regional and national borders, which is why areas far from any active fire can still be under air-quality alerts.
Can smoke make you sick even if you cannot see or smell it?
Yes. Smoke can be diluted enough that the sky looks clear, while fine particulate matter (PM2.5) and gases are already present in the air you breathe. That is why it is best to check the local index rather than trust your eyes.
Do air purifiers help with wildfire smoke?
Yes: a quality Austin Air purifier like the HealthMate Plus or Immunity Machine is one of the most effective ways to reduce smoke indoors. For smoke you need both true HEPA (for the fine particles) and activated carbon (for gases and chemicals). Particle-only filters miss the chemical part of smoke.
What is the best type of purifier for smoke?
A heavy-duty unit that combines medical-grade HEPA with a substantial amount of activated carbon, like the Austin Air HealthMate Plus or Immunity Machine.
Windows open or closed during smoke?
Closed. Open windows let smoke in and undo the benefit of a purifier. Use fans or AC on recirculate to stay cool.
Is it safe to exercise or go outside during smoke?
When there is visible smoke or the index is in the unhealthy range, avoid outdoor exercise: it makes you breathe in more smoke. If you must go out, keep it brief and wear a fitted FFP2 (or N95).
This guide is for general information only and is not a substitute for medical advice or the guidance of local public-health and emergency authorities. During a wildfire or an air-quality emergency, always follow the instructions of your local authorities. The information reflects general public-health guidance.