5.9 — Wildfire

The single most important thing about wildfire is that the decision to leave must be made much earlier than instinct suggests.

Fire moves faster than people expect — driven by wind, uphill, and through dry fuel — and the roads out become impassable while the fire is still some distance away, because of smoke, traffic and falling trees.

Almost everybody who dies in a wildfire died while leaving late.

The decision, made in advance

Two options, and you choose one in advance and commit to it.

Leave early, at the first warning — before there is fire visible, before it is confirmed to be coming your way.

Or stay and actively defend a property that has been genuinely prepared for it, with the equipment, water supply and physical capability to do so.

And the failure mode is the third option, which people take by default: wait, watch, and leave when it looks serious.

That is the one that kills people.

For almost everybody, the correct choice is leave early. Defending is for prepared properties with prepared, physically able people, and it is not the default.

Before the season

Eight things, in order of value.

Clear vegetation and flammable material from around the building. The immediate zone closest to the structure matters most: nothing flammable against the walls, no wood piles, no dry plants, no dead leaves in gutters or on the roof.

Cut back overhanging branches.

Clear gutters and roof valleys of leaf litter. Embers landing in gutters is one of the commonest ignition routes.

Screen vents and gaps. Fine metal mesh over vents, under eaves and around decks stops embers entering, and ember entry — not the fire front — destroys most houses in a wildfire.

Store fuel and gas cylinders away from the building.

Have hoses that reach every side of the building, and a water supply that does not depend on mains pressure or electricity — mains water frequently fails.

Know two escape routes.

And prepare the go-bag (9.2), kept ready during the season.

The warning signs

Smoke on the horizon, and which way it is moving.

Ash or embers falling — this means the fire is close and you should already have gone.

A sudden change in wind direction, which is what turns a fire that was passing you into a fire coming at you.

Animals moving.

And official alerts. Register for them where they exist.

Leaving

Go early. Go when you are told, or before.

Wear: long sleeves, long trousers, sturdy boots, and natural fibres — cotton or wool. Synthetics melt onto skin. Cover your head, and have a mask or cloth for smoke.

Take: documents, medication, phone and charger, water, pets, and the bag.

Close windows and doors, and leave internal doors closed — it slows fire spread if the building is entered by embers.

Turn off gas.

Leave lights on so the building is visible in smoke.

Do not lock gates, so firefighters can access.

And drive with headlights on and windows closed, air on recirculate.

If you are trapped

Genuinely dangerous, and there are actions that improve survival.

In a vehicle:

Do not drive through flames.

Park in the largest clear area available — a ploughed field, a car park, a gravel area — away from vegetation.

Stay in the vehicle. This is counter-intuitive and it is correct: the vehicle offers substantial protection from radiant heat, which is what kills, and the fuel tank exploding is far less likely than people believe.

Close windows and vents, turn off the engine, get low below window level, and cover yourself with a wool blanket if you have one.

Wait for the front to pass, which is usually a matter of minutes.

On foot:

Move downhill and away from the direction of spread — fire moves fastest uphill.

Get to already-burned ground if you can reach it safely. It cannot burn again and it is the safest place there is.

Or to a large clear area: a road, a rock field, a body of water.

If there is a river, lake or dam, get into it and keep your head down and wet.

And as a last resort, in a depression or ditch, face down, covered with soil or a non-synthetic cloth, and cover your face — the greatest danger is inhaling superheated air.

In a building:

If you are caught and cannot leave, staying inside a substantial building is usually better than being outside in the open, because it shields you from radiant heat while the front passes.

**Fill baths and sinks with water. Close everything. Move to the side of the building furthest from the fire's approach. Get low.

And go outside after the front has passed to extinguish spot fires — because the building frequently catches afterwards from embers rather than from the fire front itself.

Smoke

A hazard well beyond the fire area, and it affects far more people than the flames.

Stay indoors, windows closed, air conditioning on recirculate.

Use a proper particulate mask if you must go out — a cloth mask does very little against fine smoke particles.

People with asthma, heart conditions or lung disease should have medication available and should not exert themselves outdoors.

And create one clean room if smoke persists for days — one room, sealed as well as possible, with a filter if available.

After

Do not return until told it is safe.

Hot spots, weakened trees, ash pits that are still burning underground, damaged structures and unstable ground are all invisible.

And watch for landslides afterwards (5.8) — burned slopes lose the vegetation that holds them and fail in the first rains.

What to do with this page

Decide in advance: leave early, or defend a prepared property. The default of waiting and watching is the one that kills people.

Ember entry destroys most houses, not the fire front. Clear the gutters, screen the vents, clear the immediate zone.

Natural fibres. Synthetics melt.

Trapped in a vehicle: stay in it, in the largest clear space, below window level.

And already-burned ground is the safest place there is.

Next: 5.10 — extreme heat and extreme cold, which kill more people than most of the dramatic hazards and get much less attention.