Four fire engines and around 25 firefighters tackled a blaze at a house converted into flats on Buckingham Road in Hackney.
Part of a three-roomed flat on the first floor of the mid-terraced house was damaged by the fire. One woman left the building before the Brigade arrived and was taken to hospital by London Ambulance Service crews.
The alarm was raised when a member of the public saw smoke and flames coming from the flat and a person attempting to extinguishing the fire.
The Brigade's Fire Investigators believe the fire was caused by the unsafe disposal of smoking materials.
Station Commander Paul Eastland, who was at the scene, said: “On arrival, fire crews saw smoke issuing from the first floor. Firefighters wearing breathing apparatus located the source of the blaze in the front room and worked hard to stop it spreading to the other flats.
“We’d rather you didn’t smoke at all, but if you are a smoker, it’s absolutely vital you ensure your cigarette is completely out when you’ve finished smoking it.
“If you don’t, you risk causing a fire which could not only destroy your home, but also cost you your life.
"We would also like to remind people to never try to tackle a fire yourself. Leave it to the professionals. As soon as you become aware of a fire in your property, get out, stay out, close the door behind you and call 999."
The Brigade was called at 1046 and the fire was under control by 1156. Fire crews from Islington, Shoreditch and Homerton fire stations attended the scene.