UPDATE: A blaze south of Banning burned 45 acres and sent one firefighter away in an ambulance to an area hospital today.
The firefighter was transported in an air ambulance and treated for heat exhaustion, Riverside County Fire Department spokeswoman Jody Hagemann said.
The "Twin" fire, which was contained this afternoon, started south of Banning on Highway 243 near Twin Pines Road.
It shut down Highway 243 between Wesley and Poppet Flats Rd for most of the day. The highway is now open, but traffic is being controlled, according to CalTrans.
"Motorists are urged to use caution and yield to fire equipment working in the area," said Hagemann.
No structures were threatened and the cause is under investigation.
"Resources committed overnight on the incident include two engines and two inmate fire crews," Hagemann added.