Four fire engines and around 25 firefighters responded to a fire at an assisted living block on Tomswood Hill in Ilford.
Part of a three roomed flat on the second floor was damaged by the fire. One person left the building before the arrival of the Brigade. There were no reports of any injuries.
The fire is believed to have been accidental and caused by combustible materials left too close to an electric heater.
A London Fire Brigade spokesperson said: “The rise in energy costs means there’s a very real risk of heating-related fires. We know that people will turn to alternative ways to keep their families warm overnight without turning on the heating, we just want to make sure that people are staying safe at the same time.
“We know that people may want to use portable heaters to heat just one room. It’s important to follow the manufacturer’s instructions and ensure these items are safety registered and in good working order. If you’re using these items around children always supervise them carefully and place heaters somewhere where they won’t be accidentally knocked over and away from anything that could catch fire."
The Brigade was called at 1108 on Saturday and the fire was under control by 1235. Firefighters from Woodford, Ilford and Barking fire stations attended the scene.