Officials are asking residents to exercise extreme caution when using appliances like generators and barbecues to heat up their homes, after two people died from carbon monoxide poisoning and several others were taken to hospital overnight.

Toronto Deputy Chief Mike McCoy said Tuesday morning that Toronto Fire Services responded to 110 calls relating to carbon monoxide issues during the previous 24 hours. The department typically deals with about 20 carbon monoxide-related calls per day.

“I can’t stress it enough: any appliance in the home that burns, whether it’s a barbecue or a gas appliance or a stove, if the home stays closed and there’s no way to bring fresh air in and oxygen, you’re going to run into a CO (carbon monoxide) issue,” he said, adding that he believes the issue is going to get worse.

Even the carbon monoxide emitted by candles can lead to poisoning if they’re left burning for an extended period of time without fresh air flowing into the home, he said.

“It’s known as the silent killer, that’s the real danger, people don’t see it coming,” he said.

A 52-year-old man and his 72-year-old mother died on Monday in Newcastle Ont., from carbon monoxide poisoning after running a gas-powered generator in their garage to supply electricity to heat their house. Although there was no access to the house from the garage, the fumes still got inside the home.

On Tuesday afternoon, Toronto EMS took another two individuals to hospital for carbon monoxide poisoning after responding to a call near the Allen Road and 401 area.

Police say the victims, a 76-year-old woman and 12-year-old child, were using a charcoal BBQ to heat up their home and are being treated for non life-threatening injuries.

McCoy says placing generators inside a garage, particularly with poor ventilation, should be avoided entirely.

On Monday night in Toronto, 11 people, including a 2-year-old girl, were taken to hospital showing signs of carbon monoxide poisoning.

McCoy say many of the calls for carbon monoxide issues come from elderly people who leave appliances running for days without allowing fresh air into their homes.

“People have to pay attention to this, it’s very serious,” he said.

With files from The Canadian Press.