Firefighters were called to a suspected carbon monoxide leak at a flat on Mountfield Road in East Ham.
A carbon monoxide alarm sounded and crews used specialist equipment to confirm elevated readings of carbon monoxide on arrival believed to have been caused by barbecue coals being burnt.
The gas supply was isolated, and crews ventilated the property and carried out a sweep of the building to confirm that no further elevated readings were found. A woman was taken to hospital and two further people were treated on scene by London Ambulance Service crews.
A London Fire Brigade spokesperson said: “You can't taste, see or smell CO fumes, but it can kill in minutes.
"It's really important to fit a CO alarm in all rooms containing fuel burning appliances, ensuring that the alarm is able to be heard throughout your home. When sleeping, it is important that your alarm would wake you if it sounds.
"It’s also a good idea to familiarise yourself with the signs of carbon monoxide poisoning and learn what to do if you suspect someone may be affected.”
The Brigade was called at 0842 and the fire was under control by 1037. Two fire engines from East Ham and Plaistow and two fire rescue units from Bethnal Green and Lewisham fire stations attended the scene.
CO poisoning symptoms:
These symptoms also apply to your pets – so keep an eye on them too. Poisoning symptoms can easily be confused with just feeling unwell, which is why CO poisoning is so dangerous, and so often missed.