Three people were rescued by firefighters from a blaze in a maisonette in Archers Drive, Enfield.
Two fire engines and around 10 firefighters tacked the fire. Part of the first floor of the maisonette was damaged.
Two people were treated at the scene by London Ambulance Service and one man was taken to hospital.
The Brigade was called at 2333 and the fire was under control by 0037.
Crews from Enfield Fire Station attended the incident.
The cause of the fire is under investigation.