Seven fire engines and around 50 firefighters were called to a grass fire on Hounslow Heath.
Approximately three hectares of grass and shrubland were alight.
A London Fire Brigade spokesperson said: "During the hot weather we are attending a large number of grass fires across London.
"We’re asking the public to take care not to drop cigarettes or matches on dry grass and to keep a very close eye on barbecues.
"Dropped glass can also start fires as the sun can magnify the sun’s rays.
"Grass fires can quickly spread and cause serious damage, so if you see grass smouldering, please call 999 immediately.”
The Brigade was called at 1804 and the fire was under control at 2132, but crews will remain on scene overnight. Fire crews from Twickenham, New Malden, North Kensington, Norbury and surrounding fire stations attended the scene.