Carbon monoxide has become a deadly problem for some New Brunswick residents trying to cope with the aftermath of this week’s ice storm. Officials are calling it “a silent killer,” and they’re warning those left without power to be careful.

“We can't say (it) enough,” said Robert Duguay of New Brunswick EMO. “The risk that represents using inappropriate heating sources in a house. We encourage people to avoid that and take refuge to a shelter, warming centres.”

Two people have been found dead in two separate northern New Brunswick homes after they were poisoned by carbon monoxide. Seven others have been sent to hospital, seriously ill after being exposed to high levels of the gas. 

“The only way that you know that you're inhaling it is if you're burning something indoors that's not properly ventilated," said Barbara MacKinnon, president of the New Brunswick Lung Association.

The gas has no smell, colour or taste. But it doesn't take long to become deadly.

“You might start to get symptoms of maybe dizziness, nausea, confusion but of course if you think that that's another cause and you don't get out of your house or stop the source then it can lead to unconsciousness and death,” said MacKinnon.

The gas is also being blamed for two deaths in Dartmouth on Friday. Officials traced that to a faulty furnace.

But the risk is especially high for those who remain off the grid in New Brunswick. Some are turning to generators, woodstoves, or barbeques to eat and stay warm. But if those appliances are not properly ventilated, homeowners may not know what's happening around them until it’s too late.

Experts say it's a warning we should all heed.

"You should always have a carbon monoxide detector in your house, so if you have any source of combustion on your house, you should have one of those," said MacKinnon.

Provincial emergency officials say if you don't have power and are in need of food and warmth, go to a warming station rather than taking any risks.

"Wherever you are – we understand,” said Duguay. “You're not alone. There's some help. There's some assistance."

With files from CTV Atlantic’s Laura Brown.