Wildfires are uncontrolled fires that burn through forests, grasslands, shrublands, peatlands or other natural vegetation. They can spread rapidly when dry vegetation, high temperatures, low humidity and strong winds create favourable fire conditions.

Wildfires are dangerous not only because of the flames. They can produce thick smoke, toxic gases, extreme heat, falling trees, flying embers, poor visibility, property destruction and dangerous air pollution. Smoke can also travel far beyond the area where the fire is burning.

A wildfire can change direction and intensity quickly, making early preparation and following official evacuation instructions extremely important.

WHAT IS A WILDFIRE?

A wildfire is an uncontrolled fire that spreads through vegetation or natural areas.

Wildfires may occur in:

Forests
Grasslands
Shrublands
Mountains
Dry agricultural areas
Peatlands
Areas where forests meet residential communities

Some fires occur naturally, while many are started by human activities. The exact causes vary considerably between regions. Recent U.S. Forest Service research, for example, found that human-caused ignitions account for more than 60% of recorded wildfires in the western United States.

HOW DO WILDFIRES START?

For a wildfire to start and spread, three basic elements are required:

FUEL + OXYGEN + IGNITION SOURCE

Vegetation provides the fuel, oxygen comes from the atmosphere, and an ignition source provides the initial heat.

1. LIGHTNING

Lightning can ignite vegetation, particularly during hot and dry conditions.

A lightning strike can start a fire in:

Trees
Dry grass
Shrubs
Forest litter
Dead vegetation

Dry thunderstorms can be particularly dangerous because lightning may occur with little rainfall to suppress a newly started fire.

2. CAMPFIRES AND OUTDOOR BURNING

Human activities are an important source of wildfire ignitions.

Potential sources include:

Unattended campfires
Burning rubbish
Agricultural burning
Cigarettes
Fireworks
Outdoor cooking
Sparks from equipment

A fire that appears extinguished may still contain hot embers capable of reigniting vegetation.

3. VEHICLES AND MACHINERY

Hot vehicle components, machinery and mechanical equipment can ignite dry vegetation.

Sparks can also be produced by:

Chainsaws
Grinders
Welding equipment
Agricultural machinery
Construction equipment

The risk becomes greater when equipment is operated near extremely dry vegetation during windy conditions.

4. POWER LINES AND ELECTRICAL EQUIPMENT

Electrical faults, damaged infrastructure or equipment can sometimes start vegetation fires.

Strong winds can also cause trees or branches to contact electrical infrastructure, creating additional fire hazards.

5. INTENTIONAL IGNITION

Some wildfires are deliberately started.

This may include:

Arson
Intentional burning
Illegal land clearing
Deliberate destruction of property

6. HOT, DRY AND WINDY WEATHER

Weather does not necessarily start a fire by itself, but it can dramatically influence how easily vegetation ignites and how quickly an existing fire spreads.

The combination of:

hot temperatures + dry vegetation + low humidity + strong winds

can create extremely dangerous fire conditions.

WHY DO WILDFIRES SPREAD SO QUICKLY?

Several factors can accelerate wildfire spread.

DRY VEGETATION

Dry grass, leaves, branches, shrubs and dead trees provide readily available fuel.

STRONG WINDS

Wind can:

Push flames forward
Carry burning embers
Start spot fires ahead of the main fire
Change the direction of fire spread
Make firefighting more difficult

LOW HUMIDITY

Dry air removes moisture from vegetation, making it easier to ignite and burn.

HIGH TEMPERATURES

Hot conditions can dry vegetation and increase fire danger.

STEEP TERRAIN

Fire can spread rapidly uphill because flames and hot air preheat vegetation above the fire.

DROUGHT

Long periods without sufficient rainfall can dry vegetation and increase the amount of combustible material available to a fire.

THE MAIN DANGERS OF WILDFIRES

Wildfires can produce multiple hazards simultaneously.

1. EXTREME HEAT AND FLAMES

The most obvious danger is direct exposure to fire.

Extreme heat can cause:

Severe burns
Heat exhaustion
Heatstroke
Dehydration
Respiratory distress
Death

People should never attempt to approach an active wildfire unless they are trained and authorised emergency personnel.

2. WILDFIRE SMOKE

Smoke is one of the most widespread dangers associated with wildfires.

Wildfire smoke contains a complex mixture of fine particles and gases produced by burning vegetation, buildings and other materials.

Smoke exposure can cause:

Coughing
Wheezing
Difficulty breathing
Eye irritation
Sore or irritated throat
Runny nose
Headaches
Fatigue
Chest discomfort
Asthma attacks
Increased cardiovascular and respiratory problems

Smoke can travel considerable distances, meaning people far away from the actual flames can still experience unhealthy air quality.

3. FINE PARTICULATE MATTER

Very small particles in wildfire smoke can penetrate deep into the respiratory system.

This is particularly concerning for:

Children
Older adults
Pregnant people
People with asthma
People with COPD
People with heart disease
People with other chronic conditions

CDC advises people to reduce exposure to wildfire smoke and monitor local air-quality information.

4. FLYING EMBERS

Strong winds can carry burning embers well ahead of the main fire.

These embers can ignite:

Roofs
Dry vegetation
Wooden structures
Vehicles
Outdoor furniture
Other combustible materials

This is one reason wildfire can spread rapidly into residential areas.

5. RAPID FIRE SPREAD

Wildfires can change direction and spread faster than expected.

Strong winds can suddenly push flames into new areas.

A fire that appears distant can therefore become a serious threat surprisingly quickly.

6. POOR VISIBILITY

Heavy smoke can significantly reduce visibility.

This creates dangers for:

Drivers
Pedestrians
Emergency responders
Aircraft
People attempting to evacuate

Smoke-covered roads can make evacuation much more difficult.

7. PROPERTY DESTRUCTION

Wildfires can destroy:

Houses
Farms
Vehicles
Electrical infrastructure
Roads
Communication systems
Forests
Agricultural land

Communities located near vegetation, forests and grasslands can be particularly vulnerable.

8. FALLING TREES AND STRUCTURAL DEBRIS

Fire can weaken trees and structures.

After a fire, apparently standing trees may suddenly fall.

Damaged buildings may also collapse unexpectedly.

Therefore, entering a burned area without official clearance can be dangerous.

9. POWER OUTAGES

Wildfires can damage:

Power lines
Electricity substations
Communication infrastructure
Water systems

Large fires may therefore cause prolonged disruption even after the flames have been controlled.

10. TOXIC ASH AND DEBRIS

After a wildfire, ash can contain contaminants from burned vegetation, buildings, plastics, vehicles and other materials.

People should avoid unnecessary contact with ash and follow official cleanup guidance.

WARNING SIGNS OF HIGH WILDFIRE DANGER

Recognising dangerous conditions early can provide valuable preparation time.

Important warning signs include:

1. VERY DRY VEGETATION

Grass, leaves and shrubs may appear extremely dry and easily break apart.

2. HOT WEATHER

Long periods of high temperatures can dry vegetation and increase fire danger.

3. LOW HUMIDITY

Very dry air can remove moisture from vegetation.

4. STRONG OR GUSTY WINDS

Wind can dramatically increase fire spread.

5. SMOKE

Unusual smoke or a growing smoke column may indicate a nearby fire.

6. FLAMES OR GLOWING VEGETATION

Visible flames or an orange glow in a forested area should be treated as a serious warning.

7. FALLING ASH OR EMBERS

Ash or burning embers can indicate that the fire is nearby or spreading.

8. OFFICIAL FIRE WEATHER WARNINGS

Authorities may issue fire-weather watches, warnings or other alerts when weather and fuel conditions are favourable for dangerous fire behaviour. Terminology varies by country.

HOW TO STAY SAFE BEFORE A WILDFIRE

Preparation should begin before a fire threatens your community.

1. KNOW YOUR EVACUATION ROUTES

Identify several possible ways to leave your area.

Do not depend on only one road because roads may become blocked by:

Fire
Smoke
Fallen trees
Traffic
Debris

CDC recommends knowing community evacuation plans, identifying multiple routes and locating potential shelters.

2. PREPARE AN EMERGENCY BAG

Prepare supplies that can be taken quickly during an evacuation.

Include:

Drinking water
Non-perishable food
Medicines
First-aid supplies
Mobile phone
Power bank
Flashlight
Batteries
Important documents
Cash
Hygiene products
Basic clothing
Essential items for children
Pet supplies

Keep the emergency bag somewhere that is easy to reach.

3. PREPARE FOR SMOKE

Consider having appropriate respiratory protection available.

For people who must be outdoors during heavy wildfire smoke, CDC recommends a properly fitted, approved respirator such as an N95 or P100 where appropriate. Ordinary dust masks, bandanas and wet cloths do not provide equivalent protection against fine wildfire smoke particles.

4. CREATE A FAMILY EVACUATION PLAN

Your family should know:

Where to meet
Which routes to use
Where shelters are located
How to contact each other
Who will assist children or elderly relatives
How pets will be evacuated

Practise the plan before an emergency.

5. PREPARE PETS AND LIVESTOCK

Do not wait until the last minute.

Prepare:

Transport carriers
Food
Water
Medicines
Identification
Leashes
Important veterinary information

CDC recommends including pets and livestock in wildfire evacuation planning.

6. REDUCE VEGETATION AROUND YOUR PROPERTY

Where local regulations and conditions allow, reduce easily combustible vegetation around buildings.

Useful measures can include:

Removing dead leaves
Clearing dry branches
Keeping vegetation maintained
Cleaning gutters
Keeping combustible materials away from buildings
Maintaining defensible space where appropriate

The exact requirements should follow local fire-safety regulations.

HOW TO STAY SAFE DURING A WILDFIRE

1. FOLLOW OFFICIAL WARNINGS

This is one of the most important rules.

Monitor:

Local emergency alerts
Fire department announcements
Meteorological information
Government emergency websites
Official evacuation instructions

Do not rely solely on social media rumours.

2. EVACUATE WHEN ORDERED

If authorities issue an evacuation order:

LEAVE IMMEDIATELY.

Do not wait until flames are visible at your property.

Evacuation routes can become dangerous or blocked as a wildfire spreads.

CDC and Ready.gov both advise following official evacuation instructions and leaving when ordered.

3. STAY INDOORS WHEN AUTHORITIES ADVISE IT

If there is heavy smoke but no evacuation order, staying indoors can reduce smoke exposure.

Close:

Windows
Doors
Other openings

Where possible, use air filtration and keep outdoor air from entering unnecessarily.

4. KEEP INDOOR AIR CLEANER

During severe smoke conditions:

Close windows and doors.
Use a suitable air cleaner if available.
Use air-conditioning on recirculation where appropriate.
Avoid activities that generate additional indoor particles.
Avoid smoking indoors.
Avoid burning candles, incense or wood indoors.

CDC recommends creating a cleaner-air room when possible.

5. LIMIT OUTDOOR ACTIVITY

When smoke levels are unhealthy, avoid unnecessary outdoor activities.

Exercise can increase the amount of polluted air you breathe.

Pay particular attention to children and people with respiratory or cardiovascular conditions.

6. DO NOT DRIVE INTO A WILDFIRE AREA

Avoid driving toward:

Flames
Thick smoke
Burning vegetation
Closed roads
Evacuation zones

Follow designated evacuation routes and instructions from authorities.

IF YOU ARE TRAPPED BY A WILDFIRE

Being trapped by wildfire is an emergency.

Immediately:

Call the local emergency service if communication is available.
Give your exact location.
Follow emergency responders' instructions.
Move away from vegetation and fuel if a safe route exists.
Do not attempt to drive through flames unless instructed by emergency authorities.

Ready.gov advises people who become trapped to call emergency services and provide their location, while recognising that emergency response may be delayed or impossible in rapidly developing fires.

WHAT TO DO AFTER A WILDFIRE

The danger can continue after the flames disappear.

1. DO NOT RETURN TOO EARLY

Do not return to an evacuated area until authorities say it is safe.

Smoke, ash, unstable structures, electrical hazards and hot spots may remain.

2. WATCH FOR HOT ASH AND EMBERS

Burned areas may contain:

Hot ash
Hidden embers
Smouldering vegetation
Heat pockets

These can cause burns or restart fires.

Ready.gov specifically warns people to avoid hot ash, charred trees, smouldering debris and live embers.

3. BE CAREFUL AROUND DAMAGED BUILDINGS

Fire can weaken structures even when they appear intact.

Look for:

Cracked walls
Burned roofs
Collapsed sections
Damaged electrical systems
Broken glass
Unstable trees

Do not enter seriously damaged structures without appropriate clearance.

4. CONTINUE MONITORING AIR QUALITY

Smoke may remain in the atmosphere for days after a wildfire.

Continue monitoring local air-quality information even after the fire has been controlled.

5. PROTECT YOURSELF DURING CLEANUP

Wildfire cleanup can expose people to:

Ash
Dust
Sharp debris
Chemicals
Electrical hazards
Unstable structures
Damaged trees

Use appropriate protective equipment and follow local authorities' cleanup guidance.

Children should not participate in wildfire cleanup activities.

HEALTH WARNING SIGNS AFTER SMOKE EXPOSURE

Seek medical attention if smoke exposure causes concerning or persistent symptoms such as:

Difficulty breathing
Shortness of breath
Persistent coughing
Wheezing
Chest pain
Severe weakness
Worsening respiratory symptoms

Severe breathing difficulty or other medical emergencies require immediate emergency medical care.

HOW TO REDUCE WILDFIRE RISK

Wildfires cannot always be prevented, particularly when natural ignition such as lightning occurs. However, many human-caused ignitions can be reduced.

Important prevention measures include:

🔥 Avoid careless outdoor burning

Never leave a fire unattended.

🚭 Dispose of cigarettes properly

Never throw burning cigarettes onto dry vegetation.

🏕️ Extinguish campfires completely

Make sure the fire is completely out before leaving.

⚙️ Use machinery carefully

Avoid creating sparks near extremely dry vegetation during high fire-danger conditions.

⚡ Maintain electrical infrastructure

Proper maintenance can help reduce electrical ignition risks.

🌳 Manage vegetation

Removing excessive dry fuel around buildings can reduce exposure to wildfire.

📢 Follow fire restrictions

When authorities prohibit outdoor burning or activities that can create sparks, follow those restrictions.

WILDFIRE SAFETY CHECKLIST

BEFORE A WILDFIRE

✔ Know your evacuation routes.
✔ Prepare an emergency bag.
✔ Prepare medicines and important documents.
✔ Make a family communication plan.
✔ Prepare pets and livestock.
✔ Monitor local fire danger.
✔ Prepare respiratory protection.
✔ Reduce combustible vegetation around your property where appropriate.

DURING A WILDFIRE

✔ Follow official alerts.
✔ Evacuate when ordered.
✔ Stay away from the fire.
✔ Avoid smoke whenever possible.
✔ Keep windows and doors closed during smoke events.
✔ Use suitable air filtration if available.
✔ Avoid unnecessary outdoor activity.
✔ Do not drive into closed or burning areas.

AFTER A WILDFIRE

✔ Wait for official permission before returning.
✔ Avoid hot ash and smouldering debris.
✔ Stay away from unstable structures and trees.
✔ Avoid damaged electrical infrastructure.
✔ Continue monitoring air quality.
✔ Protect yourself during cleanup.
✔ Seek medical attention for serious or persistent breathing problems.

WHAT NOT TO DO DURING A WILDFIRE

❌ Do not ignore evacuation orders.
❌ Do not wait until the fire is at your doorstep before leaving.
❌ Do not drive toward flames or thick smoke.
❌ Do not enter an evacuated area without official clearance.
❌ Do not walk through burning vegetation.
❌ Do not touch fallen electrical lines.
❌ Do not allow children to play in ash or debris.
❌ Do not assume the danger is over when the flames disappear.
❌ Do not rely on ordinary cloth masks to protect against fine wildfire smoke.

CONCLUSION

Wildfires are among the most dangerous natural hazards because they can combine rapid fire spread, extreme heat, toxic smoke, flying embers, poor visibility, property destruction and dangerous post-fire conditions.

The most important causes and contributing factors include:

Lightning
Human activities
Uncontrolled outdoor fires
Machinery and equipment
Electrical faults
Dry vegetation
Drought
High temperatures
Low humidity
Strong winds

The best protection is early preparation and rapid response.

Know your evacuation routes, prepare emergency supplies, monitor official warnings and understand local fire risks. If authorities order an evacuation, leave immediately rather than waiting for conditions to deteriorate.

Wildfire smoke should also be taken seriously because it can affect people far beyond the actual fire zone.

KEY SAFETY MESSAGE

STAY ALERT, AVOID WILDFIRE SMOKE, FOLLOW OFFICIAL WARNINGS AND EVACUATE EARLY WHEN INSTRUCTED.

A wildfire may be unpredictable, but **good preparation, responsible fire prevention, early warnings and timely evacuation can significantly reduce the risk to people, homes and communities.**

22 September

THE DANGERS OF WILDFIRES: CAUSES, WARNING SIGNS AND HOW TO STAY SAFE