Firefighters attended a fire at a residential block on Ingatestone Road in South Norwood.
Part of a ground floor maisonette was damaged by fire. Part of the garden was also alight.
One adult evacuated from the flat before firefighters arrived and was treated by London Ambulance Service.
A further adult was led to safety from the first floor of the building by firefighters wearing breathing apparatus via an internal staircase. The member of the public was provided with a fire escape hood.
London firefighters were among the first in the UK to carry fire escape hoods when they were introduced in 2018 as part of improvements following the Grenfell Tower fire. The hoods provide members of the public with up to 15 minutes protection from four of the main fire gases (carbon monoxide, hydrogen cyanide, hydrogen chloride and acrolein) and can be worn by conscious or unconscious people. If more than 15 minutes protection is required then another hood can be given to each wearer. They do not provide oxygen but temporarily filter toxic smoke to make breathing easier.
The Brigade received the first of 13 calls about the fire at 1139 and Control Officers mobilised three fire engines and around 15 firefighters from Beckenham, West Norwood and Norbury fire stations to the scene. The fire was extinguished by 1227.
The cause of the fire is under investigation.