Fire chiefs have issued a red alert across Lancashire after the first heathland blaze of the year kept six crews busy for more than seven hours.
Officers say recent dry weather has increased the risk of wildfires, especially in moorland areas.
Never throw a cigarette end out of a car window, they can ruin whole fields of cropsFire service
The brigade had to commit more than 30 firefighters from five different stations to a blaze across a vast area of moorland between Darwen and the Rossendale Valley on Thursday.
Then on Friday evening another fire broke out, involving 300 metres of moorland at Whitworth.
Now a public warning has now been sounded to help prevent further outbreaks in coming weeks.
“Every year wildfires destroy thousands of acres of countryside and wildlife habitats and although some are started deliberately some are due to carelessness,” said a spokesman.
“A wildfire is an uncontrolled vegetation fire which generally involves moorland, heath, grassland, agricultural land or forestation and can have a devastating impact on the economy, environment and our resources.”
Lancashire has been hit by 69 wildfires in the past two years and the brigade says most required a large scale operation to control and extinguish.
Officers say the involvement of the public is vital to keep incidents to a minimum and they have issued guidelines to people who use the countryside to help prevent emergencies.
Carelessly discarded cigarette ends are thought to be the main cause of fires in the countryside.
“As a result smokers are urged to take extra care when disposing of them, either when walking or driving through rural areas.
“Never throw a cigarette end out of a car window, they can ruin whole fields of crops,” said the spokesman.
“The high pressure system which has been dominating the UK had the potential to bring in dry continental air. Historically this weather pattern has been linked to a higher risk of wildfires at this time of year.”