Firefighters were called to a flat fire on Diploma Avenue in East Finchley.
A small part of a five-roomed flat on the third floor of the building was damaged by fire. Firefighters led two people out of the building. A man and a woman were treated on scene by London Ambulance Service crews after suffering from smoke inhalation.
The Brigade was called at 1431 and the fire was under control by 1457. Three fire engines and around 15 firefighters from Finchley and Hornsey fire stations attended the scene.
The fire is believed to have been caused by a fault in an electric radiator.