They were called to the property in Rouge Bouillon at around 2.35 am after a neighbour was awoken by a smoke detector alarm.
Two fire engines responded to the call, but the firefighters were unable to raise the occupant of the flat and broke-in.
They found the cause of the smoke to be burnt food in the kitchen.
The man was treated for smoke inhalation.
A Fire Service spokesman said: ‘This is another example of the value of having smoke detectors in your property, especially in the bedroom.
We would advise everyone to ensure they have at least one working smoke detector in their home, and those that already own detectors to check the battery once a week.’
