It is believed that a cigarette ignited the couch that the man was sitting on, causing life-threatening burns to 80% of his body.
Reports from the scene indicate that neighbours were able to put out the fire with a garden hose and assisted the man until help arrived.
Queensland Ambulance Service paramedics treated the man at the scene, before transporting him to Gayndah Hospital.
The Sunshine Coast RACQ CareFlight Rescue helicopter was tasked to collect the patient from Gayndah Hospital at 8.40am, and delivered him to the Royal Brisbane Hospital for specialist treatment.
He travelled in a critical condition.