Smoke alarms in Blackheath enabled a woman and child to escape to safety after fire broke out in a storage heater and set clothing alight.
By the time London firefighters arrived they had managed to leave their property in Lethbridge Close.
They were treated for smoke inhalation before being taken to hospital by London Ambulance Service crews.
The blaze has damaged part of the kitchen of their three-room first floor flat.
Greenwich Watch Manager Andrew Trainor, who was at the scene, said:
The smoke alarms went off and that is what alerted everyone. The alarms were fitted by Greenwich White Watch last year and there’s no doubt they saved their lives. All the windows were shut and the whole place was smoke logged with thick smoke when crews went in. This incident is also a reminder to take care when using heaters as this fire was caused by clothes being hung up too close to a heater. Clothing, blankets and other material getting too close to heaters is a dangerous fire risk.
The London Fire Brigade was called out at 6.33 am in the morning on Wednesday 12th January and the fire was under control about three quarters of an hour later.
The incident was dealt with by four fire engines and 21 firefighters and officers from Greenwich, Lewisham, Deptford and New Cross fire stations.