Firefighters work in a paddock blackened by recent bushfires near Bookham, a small village in the Yass Shire in Australia's New South Wales state, on Thursday. [Greg Wood / Agence France-Presse]

Dozens of out-of-control fires have burned vast tracts of Australia, destroying homes and crops and killing animals, but not a single person has died.

The success of the operation to safeguard lives has much to do with a detailed guide to surviving bush blazes, along with an official danger rating system that was introduced after 173 people perished in the 2009 Black Saturday firestorm.

In addition, the Rural Fire Service is extremely active in promoting safety precautions and tells every family how to make their own survival plans.

Rob Rogers, deputy commissioner of the service for New South Wales, spent Friday morning on radio and television, bracing the nation for more to come as firefighters faced soaring temperatures in the battle to douse more than 100 fires.

"We've obviously got severe fire danger," Rogers said, running through the basic requirements of survival designed to "protect the lives of your family".

"Prepare, act, survive," say the guidelines. "The majority of deaths during bushfires result from people trying to leave their homes at the last moment."

The danger ratings system culminates in severe, extreme and catastrophic conditions, which are used to determine whether to evacuate, or stay and fight.

A severe warning was declared in parts of Victoria state on Friday with a heat wave expected to intensify over the weekend.

Catastrophic ratings were in force in some areas last Tuesday - officially billed as the worst fire day in New South Wales history - but no one died.

Anyone doubting the risks, however, is told in the Bushfire Survival Plan, "A bushfire can be a terrifying situation. Strong gusty winds, intense heat and flames will make you tired quickly.

"The roaring sound of the fire approaching will deafen you. Embers will rain down, causing spot fires all around you. Power and water may be cut off. You may be isolated. It will be dark, noisy, and extremely physically and mentally demanding.

"If you have any doubts about your ability to cope, you should plan to leave early."

Despite the severity of the warnings, plenty of people decide to stay and defend their homes. And the guidelines, while noting that everyone must flee in the face of a catastrophic rating, tell residents how to do it.

An emergency survival kit, protective clothing and a home that is well prepared are integral to any plan.

The exhaustive kit includes a portable battery-operated radio, waterproof flashlight, spare batteries, candles with waterproof matches, first aid kit, pocket knife, important documents and at least three liters of water per person per day.

Loose-fitting clothing made from natural fibers, heavy cotton drill or denim is advised. Synthetic fabrics, such as nylon, can easily melt or burn.

Other items include a wide-brimmed or hard hat to "stop embers from dropping onto your head or down the back of your shirt", goggles, gloves, a mask or cloth to cover nose and mouth, and sturdy work boots.

Preparations to defend a home, regardless of whether occupants choose to fight or flee, are also serious, with Neighborhood Safer Places designated as a last resort when the flames rise.

The advice includes planting trees and shrubs with low oil content that are less likely to ignite, cutting overhanging vegetation, replacing damaged roof tiles, building non-combustible fences and keeping grass short.

Hoses should be long enough to reach everywhere, flammable items must be stored away from the house and doormats should be non-combustible.

Despite fires raging across southeast Australia, few homes have been destroyed, although thousands of livestock have died and more than 350,000 hectares of land have been scorched.