UPDATE: THREE teenage boys have been charged with deliberately lighting a fire in bushland in Sydney's west.
Officers were called to a fire in bushland behind Chestnut and Sedgman Crescent in Shalvey at about 1.15pm (AEDT) yesterday, on a day there was a total fire ban across the state and "catastrophic" fire conditions.
About 15 trucks from the Rural Fire Service and five police cars rushed to the scene.
Temperatures soared well into the 40s in western Sydney yesterday as the state was hit with a heatwave and extreme fire conditions.
It took firefighters two-and-a-half hours to bring the fire under control, police said.
It burnt out 10 hectares in the process, although no one was injured during the fire and no properties damaged.
Three teenage boys were arrested near the fire and questioned at Mt Druitt police station.
A 14-year-old and two 15-year-olds have been charged with intentionally causing a fire, being reckless to its spreading and causing or setting fire to the property of another.
They were granted strict conditional bail to appear in Parramatta Children's Court on January 29.