A mans been flown from John Hunter Hospital with serious burns, following an incident with a backyard fire. 

An accelerant was thrown onto the flames around 12.45am on Thursday morning. 

The 47-year-old man treated on scene by NSW Ambulance paramedics before being transported to the John Hunter Hospital. 

He was then placed into a medically induced coma and was airlifted to Royal North Shore Hospital in a serious condition.