High temperatures and little rainfall are perfect conditions for bush fires to start naturally or accidentally

Where they occur: Mostly in Australia and parts of the USA

Occurrences per year: There were 6,000 bushfires in Australia from 2003 to 2004

Size: 8,595,800 acres were burnt in Australia from 2003 to 2004

Max speed: 24kmph (15mph)

Casualties: In 2003-4, seven people died in Australia

The burning of a woodland area is called a bushfire in Australia and a forest, wild or brush fire in other parts of the world. Bushfires are very common in Australia, where many regions have high temperatures and restricted rainfall for extended periods of time, making perfect bushfire conditions. They are often caused by human carelessness - through a discarded cigarette or campfire - but they can also be started by lightning strikes, or spontaneous combustion, when dry material is ignited by the heat of the sun.

Bushfires are unpredictable, picking up speed and changing course as wind direction alters. Fire fighters strip land of fuel to form firebreaks and flying water tankers can tip thousands of gallons of water on to the fire to try and stop it spreading. Once a fire takes hold, its progress will be aided by low humidity, high air temperature and strong winds, as it devours everything in its path.