A water-dumping helicopter was brought in to help firefighters tackle a series of moor fires which threatened wildlife on protected land in the Pennines.
West Yorkshire Fire Service said dozens of firefighters have been fighting outbreaks on the moors near Huddersfield in the last 24 hours.
Part of the affected moorland above the villages of Marsden and Slaithwaite is managed by the National Trust and parts are designated as a Site of Special Scientific Interest.
A fire service spokeswoman said there had been three separate blazes on the moors in the last two days.
At their peak, more than 50 firefighters were brought in and firefighters and the National Trust arranged for a helicopter to dump water on the affected areas.
The total area affected is more than 500 hectares spread over 1.5km of moorland.
The spokeswoman said she could not comment on reports at least one of the fires had been started deliberately.
She said: "If this hot weather is set to continue, this could just be the start."
But she said the teams on the moor, who were using beaters and water, were now on top of the situation and the number of crews committed to the operation was being scaled down.
