Five fire engines and around 35 firefighters were called to a flat fire on North Mall in Edmonton.
Part of a three-roomed flat on the seventh floor of the building was damaged by fire. Four children and a woman left the property before the Brigade arrived and were treated on scene by London Ambulance Service crews.
The Brigade was called at 2340 and the fire was under control by 0031. Fire crews from Tottenham, Enfield, Chingford, Walthamstow and Hornsey fire stations attended the scene.
The cause of the fire is under investigation.