Two adults and two children escaped after a fire broke out in a house on Barlow Road in Hampton in Twickenham, TW12 in the early hours of Saturday morning.
A man was suffering from smoke inhalation and was treated by London Ambulance Service at the scene.
The fire severely damaged part of the ground floor of the house.
Four fire engines and around 20 firefighters were called to the fire at 0123 .
Fire crews from Kingston, Twickenham and Feltham fire stations were at the scene.
The cause of the fire is under investigation.