Four fire engines and around 25 firefighters were called to reports of a potential gas leak and chemical smell at a flat on Kingston Road in New Malden.
Firefighters carried out a sweep of the building to check for elevated readings of chemical substances, but none were found. Crews wearing breathing apparatus rescued a man and a woman from a flat on the third floor who were taken to hospital by London Ambulance Service crews. Around 60 people were evacuated as a precaution and the building was ventilated.
The Brigade was called at 1914 and the incident was over for firefighters by 2142. Fire crews from New Malden, Surbiton, Kingston and Sutton fire stations attended the scene.