Four fire engines and around 25 firefighters tackled a flat fire on Aberdare Gardens in West Hampstead.
Half of a three-roomed flat on the ground floor of a detached building was damaged by fire. Two people left the building before the Brigade arrived and were treated on scene by London Ambulance Service crews.
A London Fire Brigade spokesperson said: “Firefighters recommend that you have a look at our online Home Fire Safety Checker to make sure there are no hidden hazards in your home.
“The online tool will ask you a series of questions that will help us work out the level of risk in your home, or the home of someone you care for. It only takes a few minutes to get tailored advice to keep yourself and loved ones safe from fire.”
The Brigade was called at 1614 and the fire was under control by 1715. Fire crews from Paddington, Kentish Town and North Kensington fire stations attended the scene.
The cause of the fire is under investigation.