The man had to be flown to a specialist burns unit after being injured in the fire on Tuesday evening. Two other people were also injured.
Emergency services today warned people not to use accelerants on barbecues and camp fires.
Fire crews and the ambulance service were called to a house in Hopton Wafers, near Cleobury Mortimer, at 6.45pm.
Murray MacGregor from the West Midlands Ambulance service said the elderly man had suffered very serious burns.
He said: "He had active cooling before burns dressings were put in place. He was given pain relief and fluids before being airlifted to the burns centre at Queen Elizabeth Hospital Birmingham.
"A middle-aged man had also suffered burns. He was taken to the same hospital by land ambulance with the doctor travelling with the crew. He had also had active cooling and was given pain relief."
"An elderly woman who had gone to aid the other two patients was treated at the scene for less serious burns . She was discharged at the scene after assessment.
"We would ask people never to use accelerants with barbecues and similar fires."