Arsonists who have started a spate of small blazes on open ground in dry weather have been warned they are putting lives at risk.
Firefighters have been called to a series of incidents over a 24-hour period - which bosses say could have delayed them attending more serious incidents.
Just a few seconds can mean the difference between life and death for people trapped in house fires or serious road collisions.
A South Yorkshire Fire and Rescue spokeswoman said: “We treat acts of arson extremely seriously, and work closely with police to identify those responsible and to prevent further instances.
“Small fires have the potential to spread to properties and could put lives at risk. They also take up a large amount of resources when they could be needed at genuine life-threatening emergencies.
“If you spot someone starting fires or have any information about people starting fires in your area, contact Crimestoppers on 0800 555 111.”
Straw was set ablaze off Slade View, Slade Hooton, Rotherham, at 8.30pm on Wednesday.
Firefighters dealt with a rubbish fire on Oldroyd Avenue, Grimethorpe, Barnsley, which firefighters believe was also started deliberately, at 9.35pm on Wednesday.
Accidental small fires involved a bin in Endcliffe Park, Hunters Bar, at 9pm on Wednesday, and grass on fire off Washington Road, Goldthorpe, at 9.10pm on Wednesday.
A spokesman for Derbyshire Fire Service said they also dealt with a number of small fires.
Crews twice attended Bramshill Rose, Chesterfield, within several hours – a tree fire at 10.45pm on Wednesday, followed by a small fire on open ground at 2.14am yesterday.
Firefighters attended a car fire on High Street, Eckington, at 1am yesterday.
A further blaze involved 500 square metres of rough grass on Thickley Close, Shirebrook, at 5.35pm on Wednesday.
And a Volkswagen Jetta car was set alight at 4am yesterday on Halifax Road, Parson Cross.