Fire crews from Rotherham, Tankersley and Edlington stations were called out to a flat fire just after 2am on Monday.
On arrival at the flat on Hague Avenue in Rawmarsh, Rotherham the occupant was already outside.
Firefighters wearing breathing apparatus used hose reels to extinguish the fire which was in the bedroom.
The man was taken by ambulance to hospital.
An investigation into the fire is ongoing, though it is believed to be accidental.