Although the Montreal Children's Hospital has yet to see a case of carbon monoxide poisoning this season, health officials are seizing the opportunity to caution Montrealers about the imminent danger of leaving cars idling in inclement weather.

In a statement issued Saturday, the McGill University Health Centre provided safety tips for those planning on using their cars after a heavy snowfall.

For starters, experts say that drivers should remove snow from the car prior to starting the engine and ensure that the exhaust pipe is not blocked. 

"After a large snowfall, the exhaust pipe can become blocked by snow, and idling can produce carbon monoxide poisoning inside the car -- leading to death," Sandra Sciangula, an MUHC spokesperson, said in the statement. 

In fact, cars generally should not be left running inside the garage, even if the garage door is open. 

Although carbon monoxide is an odourless, colourless, and tasteless toxic gas, there are a number of signs that could help point to its presence.

Mild poisoning can cause headaches, dizziness, nausea, vomiting, and fatigue. More serious exposure can result in fainting, convulsions, coma, and even death.

When it enters the body, carbon monoxide bonds to the hemoglobin in the blood, preventing the natural flow of oxygen through the body. 

Some people are more susceptible to intoxication by fumes, including pregnant women, their unborn fetuses, as well as the elderly and young children. 

A concern fuelled by precedents

After a generous snowfall in March of last year, at least four Montrealers were rushed to hospital after being found unconscious in their cars.

In each case, the people were sitting inside a car partially buried in snow with the engine running.

All were treated for carbon monoxide poisoning and came close to dying.

Two people in Quebec City were less fortunate, however, found dead in their cars of suspected carbon monoxide intoxication. 

The Montreal Children's Hospital said that it has since seen several cases of carbon monoxide poisoning in children.