Firefighters were called to a suspected carbon monoxide leak at a house on Bromyard Avenue in Acton.
Two adults and a child were taken to hospital after suffering from suspected carbon monoxide poisoning.
Firefighters wearing breathing apparatus used specialist equipment to carry out a systematic sweep of the building and found elevated readings of carbon monoxide. Crews ensured no elevated readings remained before leaving the scene.
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 the property. When sleeping, it's important that your alarm can 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 1727 and the incident was over for firefighters by 2002. Two fire engines from Acton and Chiswick fire stations and two fire rescue units from Wembley and Euston fire stations attended the scene.
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.