Six fire engines and around 40 firefighters were called to a fire at a flat on Cedar Road in Enfield.
Part of a flat on the sixth floor of a 12-storey block was damaged by the fire. Firefighters wearing breathing apparatus led one man to safety. He was taken to hospital by London Ambulance Service crews.
The Brigade was called at 1420 and the fire was under control by 1514. Fire crews from Enfield, Edmonton, Hendon, Tottenham and surrounding fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.