A firefighter is in a critical condition in Royal Perth Hospital after she and a colleague were seriously burned in a plantation fire in Albany on Friday night.
The condition of her colleague has improved to stable.
AAP reports the critical woman has burns covering more than 60% of her body. The other has 40% burns.
The Royal Flying Doctor Service despatched two aircraft to Albany to transport the two women to Royal Perth Hospital.
They are both being treated by Professor Fiona Wood.
The ABC reports they were trapped in a fire truck in the Two Peoples Bay nature reserve, near Albany on Friday afternoon.
The Department of Environment and Conservation said the women were caught by a change in the wind wind.
A spokesman said the fire started on private property and spread into the nature reserve. The cause is being investigated.
The fire has now burned 1000 hectares of bushland.