FACTBOX: How to survive an Australian bush fire

SYDNEY (Reuters) - Many people survived Australia's deadliest bushfires at the weekend because they did what others would have thought insane: standing their ground and not fleeing.

Kevin Tolhurst, a "fire-behavior specialist" who helped authorities track the infernos, said the golden rule of surviving forest fires -- evacuate early or fight to the bitter end -- still stood, despite the weekend's record death toll of 126.

The University of Melbourne expert, who has studied bushfires at close quarters for 20 years, said many victims appear to have been ill prepared or to have fled at the worst time.

He gave these guidelines on how to survive an inferno:

UNDERSTAND WHAT YOU ARE UP AGAINST

Australian forest fires are terrifying, partly because native eucalypt forests spew lots of embers. In the infernos north of Melbourne, flames reached up to 50 meters (yards), creating a life-threatening zone of up to 200 meters (roughly four times the flame height) ahead of the fire front. Here, people can suffocate as heat sears the lungs, rendering them unable to function.

ESCAPE EARLY OR FIGHT TO THE END

This is the golden rule of survival in Australia's fire-prone countryside, but Tolhurst suspects it is misunderstood. Those who do not flee early must have prepared their properties well for the battle and be brave enough to keep up the fight. This means hosing down roofs and stamping out embers, anything to prevent the house from igniting, even though it may seem hopeless.

"Houses, just because of their mass, take a while to catch alight, but once they are alight they will burn with enormous intensity," Tolhurst said. "You really need to be defending yourself," he added, explaining that a house could survive if it was still in good shape by the time the fire-front raced through.

PREPARE WELL

There is no point defending a house against wild fires unless its perimeter has been cleared of flammable material, including trees, shrubs and garden beds. "You must have a safe area to work in so you can do some small-scale suppression and reduce the spot fires," Tolhurst said. Otherwise, you should evacuate while you still can. A car is a very bad place to be in a fire: "A car heats up too much. It's such a small volume of space."

GOING UNDERGROUND IS NO GUARANTEE

One man and his wife survived sheltering in a cellar, but Tolhurst said underground bunkers offered no assurance of survival, especially if they were beneath a burning house and could fill with searing heat and carbon-dioxide.

SURVIVING THE HORRIFYING CLIMAX

A fire-front can take 10-15 minutes to pass over a house, during which time you should stay away from windows where the heat radiation is most intense. Don't douse yourself and your clothes with water because you could suffer serious burns as the water close to your skin boils. Protect your lungs by breathing through a handkerchief. "The best thing is to move around and make sure embers are not coming under the door," Tolhurst said.

THE EXPERT'S VERDICT

"It's a bit hard unless you have actually experienced a bushfire. A lot of people stay and then see how scary it is and say 'there's no way I'm staying here' and then take off. We know from experience that the strategy of staying with your house, provided it is protected and well prepared, works well -- though nothing can give you a 100 percent guarantee."

(Reporting by Mark Bendeich; Editing by David Fox)