Fire chiefs in South Yorkshire are gearing up for a 24-hour strike.
Contingency firefighters have been drafted in to help provide emergency cover during the walk-out.
Crews across the county are due to begin the industrial action, called by the Fire Brigades Union, at 9am on Thursday.
It forms part of an ongoing dispute between the union and the Government over pensions and fears over aging firefighters losing their jobs if they fail fitness tests.
Chief Fire Officer Jamie Courtney said 999 calls will still be responded to but urged people to only call for help in genuine emergencies.
“Our priority will be to respond to priority calls where a life may be at risk or someone needs to be rescued,” he said.