Eight fire engines and with around 60 firefighters attended a carbon monoxide leak at a residential building on Rookwood Way in Bow.
Around 14 people left the building before the Brigade arrived and three men suffered from the effects of carbon monoxide poisoning.
Firefighters used specialist equipment to carry out a systematic sweep of the building to check for elevated readings of chemical substances. 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 1440 and the incident was over for firefighters by 1744. Crews from Stratford, Leytonstone, Homerton Stoke Newington, and surrounding 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.