Four fire engines and 21 firefighters and officers were called to a fire at a block of flats in Princeton Street, WC1R.
Part of a maisonette on the third and fourth floors of the building were damaged by fire. Three adults left the property before the arrival of the Brigade and were treated at the scene for smoke inhalation before being taken to hospital by London Ambulance Service crews.
The Brigade was called at 0759 and the fire was under control at 0953. Fire crews from Soho, Euston and Shoreditch fire stations attended the scene.
The cause of the fire is under investigation.