Firefighters rescued a woman from a fire in a hostel on Endsleigh Gardens in Camden.
Fire crews wearing breathing apparatus led the woman to safety. She was suffering from smoke inhalation and taken to hospital by London Ambulance Service crews.
Part of a bedsit on the ground floor was damaged by fire.
The Brigade was called at 2342 and the fire was under control by 0010. Firefighters from Soho, Kentish Town and Euston fire stations attended the scene. The cause of the fire is under investigation by the Police and fire officers.