Firefighters were called to a fire at a house on Park Avenue in Southall.
On arrival crews were faced with a small fire in the back garden of a mid-terraced house. One man was treated on scene by London Ambulance Service crews.
The fire is believed to have been caused by the burning of a wasps nest.
A London Fire Brigade spokesperson said: "If you are concerned about a wasp nest or an infestation in your home, please don't tackle it with fire.
"Contact your local council, Environmental Health team or a professional pest controller for advice on how to safely deal with treating pest problems."
The Brigade was called at 1243 and the fire was under control by 1258. Two fire engines and around 10 firefighters from Southall fire stations attended the scene.