In many Canadian cities shovelling your car out of the snow can be a significant setback to your morning routine.  But, in Montreal where another storm has blanketed the city with another 35 centimetres of snow this weekend, officials are sending out a public health warning about the dangers of digging out your car.

The strenuous job of snow removal can be a risk for those with health conditions but, the latest warning is not about the cold or hard work.  The concern is with how people are shovelling the snow and every year several people collapse and die from this one simple mistake.

Most people start with shovelling their car out by starting the vehicle and cranking the heat on high.  Makes sense that you would want a warm car after climbing around in the frozen temperatures.  However, most people will forget to remove the snow covering the exhaust pipe, and it can often be left to last.  When the engine runs and the exhaust has nowhere to go, it will begin filling up the cabin of the car.  The resulting carbon monoxide is colourless and odourless, and people will start driving not realising that they are breathing a lethal concentration of fumes.

The official Montreal Public Health Department warning asks citizens not to leave their car running while clearing the snow, and remove all snow that has accumulated around the tailpipe before starting the engine.