Wildfire Season: Complete Guide to Protecting Your Health from Smoke

Wildfire season is becoming longer and more intense across many regions. Smoke from wildfires can travel hundreds or even thousands of miles, affecting air quality in areas far from the actual fires. Understanding how to protect yourself and your family during smoke events is increasingly essential.

Understanding Wildfire Smoke

Wildfire smoke is a complex and dangerous mixture of gases and fine particles produced when wood and other organic materials burn. The composition varies based on what's burning, fire intensity, and weather conditions.

What's in Wildfire Smoke?

Particulate Matter (PM2.5)

The primary health threat from wildfire smoke is PM2.5—particles smaller than 2.5 micrometers (about 1/30th the width of a human hair).

• Size matters: PM2.5 is small enough to penetrate deep into lungs and enter the bloodstream
• High concentrations: Wildfire smoke can cause PM2.5 levels 10-100 times higher than normal
• Different composition: Wildfire PM2.5 may be more toxic than urban particulate matter
• Lingers for days: Particles can remain suspended in the air long after fires are extinguished

Toxic Gases

• Carbon monoxide (CO): Reduces oxygen delivery to organs and tissues
• Nitrogen oxides (NOx): Irritate airways and reduce lung function
• Volatile organic compounds (VOCs): Including formaldehyde and benzene
• Acrolein: Highly irritating to eyes and respiratory tract

When Structures Burn

When wildfires reach homes and buildings, smoke becomes even more toxic:

• Plastics release dioxins and other carcinogens
• Treated wood releases heavy metals
• Vehicles contribute battery acids and petroleum products
• These compounds can be significantly more hazardous than vegetation smoke

How Smoke Travels

Understanding smoke behavior helps you anticipate and prepare:

• Distance: Smoke regularly travels 100-200 miles; in extreme cases, thousands of miles
• Elevation changes: Smoke can move up or down with terrain and temperature
• Weather patterns: Wind direction and speed determine smoke dispersal
• Inversion layers: Can trap smoke near the ground for extended periods
• Diurnal patterns: Smoke often settles overnight and lifts during the day

Health Effects of Wildfire Smoke Exposure

Immediate Symptoms

Most people experience some symptoms when exposed to wildfire smoke:

• Eye irritation, redness, watering
• Runny nose and sinus irritation
• Scratchy or sore throat
• Coughing and phlegm production
• Headaches
• Shortness of breath
• Chest discomfort or tightness
• Unusual fatigue

Serious Health Risks

• Asthma attacks: Smoke is a powerful asthma trigger
• COPD exacerbations: Can require hospitalization
• Heart attacks: PM2.5 increases cardiovascular events within hours
• Strokes: Risk increases during high smoke exposure
• Respiratory infections: Smoke damages lung defenses against bacteria and viruses

Long-Term Concerns

Emerging research suggests repeated wildfire smoke exposure may have lasting effects:

• Reduced lung function over time
• Increased cancer risk from repeated exposure
• Cardiovascular disease progression
• Potential cognitive impacts

When to Take Action: AQI Guidelines

AQI 101-150 (Unhealthy for Sensitive Groups) - Orange

General population:

• Can continue most outdoor activities
• Watch for symptoms
• Consider reducing prolonged exertion

Sensitive groups (children, elderly, respiratory/heart conditions):

• Reduce prolonged or heavy outdoor exertion
• Take more breaks during outdoor activities
• Watch for symptoms; move indoors if they develop
• Have rescue medications readily available

AQI 151-200 (Unhealthy) - Red

General population:

• Reduce prolonged or heavy outdoor exertion
• Limit time outdoors
• Consider moving activities indoors

Sensitive groups:

• Avoid prolonged or heavy outdoor exertion
• Remain indoors as much as possible
• Keep indoor air clean
• If you must go out, minimize time outside and wear N95 mask

AQI 201-300 (Very Unhealthy) - Purple

Everyone:

• Avoid all outdoor physical activities
• Stay indoors with windows and doors closed
• Run air purifiers continuously
• Wear N95 masks if you must go outside
• Minimize outdoor exposure to minutes, not hours

AQI 301+ (Hazardous) - Maroon

Everyone:

• Remain indoors with windows and doors sealed
• Avoid all outdoor exposure
• Create a clean room with air purifier
• If evacuation necessary, wear N95/P100 respirators
• Seek cleaner air location if possible

Protecting Yourself Outdoors: Masks and Respirators

What Works: N95, KN95, and P100 Respirators

N95 respirators:

• Filter at least 95% of airborne particles
• Effective against wildfire smoke PM2.5
• NIOSH-approved (look for marking on mask)
• Disposable, typically good for 8-40 hours of use depending on conditions
• Must fit snugly with no gaps around edges

KN95 respirators:

• Chinese standard, similar to N95
• Can be effective but quality varies by manufacturer
• Look for reputable suppliers
• Test fit carefully

P100 respirators:

• Filter 99.97% of particles (better than N95)
• Often reusable with replaceable filters
• Excellent for prolonged or repeated exposure
• More expensive but cost-effective long-term
• Half-face or full-face options available

Getting a Proper Fit

Even the best respirator won't work if it doesn't fit properly:

• Try multiple brands/models: Faces vary; what fits your friend may not fit you
• User seal check: Cover mask with hands, exhale sharply—should feel resistance with no air leaking out edges
• No gaps: Respirator should seal against skin all around edges
• Facial hair: Beards and stubble prevent proper seal (even one day's growth)
• Adjust straps: Should be snug but not painfully tight
• Check seal frequently: Can shift during activity

What Doesn't Work

• Surgical masks: Designed to protect others from you, not to filter incoming air
• Cloth masks: Gaps are too large to filter PM2.5
• Dust masks: Not rated for fine particles
• Bandanas or scarves: Provide almost no protection
• Masks with exhalation valves: When COVID concerns exist (protect you but not others)

Who Should Not Rely on Respirators Alone

• Children under 2 years (N95s don't fit properly)
• People with severe respiratory or cardiac conditions (breathing resistance may be problematic)
• Those who cannot achieve proper seal due to facial structure or hair

For these groups, staying indoors with filtered air is essential.

Creating a Clean Air Refuge Indoors

During severe smoke events, your home becomes your primary protection. Optimize it:

Immediate Actions When Smoke Arrives

• Close all windows and doors
• Turn off whole-house fans and attic fans
• Close fireplace dampers
• Set air conditioner to recirculate mode (not fresh air intake)
• Seal gaps: Use towels or tape around drafty windows and doors
• Avoid creating indoor pollution: No smoking, candles, gas stoves, frying

Air Purification Strategy

Commercial Air Purifiers

• HEPA filters required: Remove 99.97% of PM2.5
• Size appropriately: Check Clean Air Delivery Rate (CADR) for room size
• Run continuously: On high setting during smoke events
• Strategic placement: Bedrooms first, then main living areas
• Keep doors closed: To maintain filtered air in priority rooms

DIY Box Fan Filter (Budget Option)

If commercial purifiers are unavailable or unaffordable:

• Attach MERV 13 or higher furnace filter to box fan
• Secure with bungee cords or tape
• Arrow on filter should point toward fan (air flow direction)
• Can reduce indoor PM2.5 by 50-90%
• Change filter when visibly dirty or airflow reduces
• Monitor fan for overheating (shouldn't run 24/7 for weeks)

Creating a Clean Room

If you can't filter your entire home, designate one room as your clean space:

• Choose a bedroom with few windows/doors
• Seal it as well as possible
• Run air purifier continuously
• Sleep and spend most time in this room during severe events
• Keep door closed except when entering/exiting

Monitoring Indoor Air Quality

• Inexpensive PM2.5 monitors ($50-150) show if your strategies are working
• Compare indoor readings to outdoor AQI
• Goal: Keep indoor PM2.5 below 35 µg/m³ (AQI 100)
• Adjust purifier placement and settings based on readings

Special Considerations for High-Risk Groups

People with Asthma

• Review asthma action plan with doctor before wildfire season
• Stock up on rescue and controller medications
• May need to increase controller medication during smoke events
• Have emergency contact numbers readily available
• Consider temporary relocation if smoke persists for weeks

People with COPD

• Extremely vulnerable to smoke
• Avoid all outdoor exposure when AQI > 100
• Have oxygen readily available if prescribed
• Know signs of exacerbation requiring medical attention
• Relocating to cleaner air may be necessary

Pregnant Women

• Wildfire smoke exposure linked to preterm birth and low birth weight
• Stay indoors with filtered air when AQI > 100
• Limit physical exertion during smoke events
• Discuss air quality concerns with obstetrician

Children

• Cancel outdoor sports and recess when AQI > 100
• Children with asthma need extra precautions
• Indoor play areas with air filtration
• Watch for symptoms: coughing, wheezing, shortness of breath
• Limit exposure even more strictly than adults

Long-Duration Smoke Events

When smoke persists for weeks, additional challenges arise:

Mental Health and Isolation

• Being trapped indoors for extended periods affects mood
• Stay connected via phone, video calls
• Maintain routines as much as possible
• Indoor exercise alternatives
• Recognize when anxiety or depression requires professional support

When to Consider Temporary Relocation

• AQI consistently above 200 for more than a week
• You're in a high-risk health category
• Home cannot be adequately sealed or filtered
• Work requires outdoor exposure
• Mental health significantly impacted

If relocating, identify cleaner air areas 50+ miles away (check AQI maps).

Preparing Before Wildfire Season

Being prepared reduces stress and health risks:

Supply Checklist

• N95 or P100 respirators for each family member (2-3 week supply)
• HEPA air purifiers or box fan + MERV 13 filters
• Replacement filters for air purifiers
• Prescription medications (30-day supply)
• Non-perishable food (if smoke limits shopping trips)
• Indoor activities/entertainment
• PM2.5 monitor (optional but helpful)

Home Preparation

• Identify and seal air leaks before season starts
• Service HVAC system, upgrade filters
• Create list of cleanest indoor spaces in your area (libraries, malls with good filtration)
• Know where to get real-time local AQI data

Health Preparation

• Annual checkup before fire season
• Update asthma/COPD action plans
• Ensure adequate medication supplies
• Know where nearest emergency room is located

After the Smoke Clears

When air quality improves:

• Wait until AQI is consistently Good or Moderate before extensive outdoor activity
• Open windows to ventilate accumulated indoor pollutants
• Clean or replace air filters that collected smoke particles
• Wipe down surfaces to remove settled particles
• If you experienced symptoms, consider medical follow-up
• Restock supplies for next event

The Bottom Line

Wildfire smoke is a serious health threat, but informed preparation and response can significantly reduce your risk. The key strategies are: monitor AQI closely, stay indoors with filtered air during smoke events, use proper respirators if you must go out, and take extra precautions if you're in a high-risk group.

Climate change is extending wildfire seasons and increasing their severity. Being prepared is no longer optional for many regions—it's an essential part of protecting your health and your family's well-being.