The last couple of summers have been among the worst for Toronto's smog problem, and idling cars are seen as one of the key contributors.

In an effort to make the air more breathable, bylaw officers are cracking down on drivers who let their cars idle.

A dozen extra officers have been called to monitor the streets, and several hundred volunteers are roaming the roads to remind Torontonians to turn off their engines.

"It's a grouping together with people from industry, from the government and its whole idea is to reduce smog...it's more than talking about it, it's putting some plans into action," said city councillor David Soknacki.

Drivers who let their cars idle for more than three minutes in a 60 minute period will be fined $130.

In the first day of the blitz, 18 drivers were fined, including one taxi driver who left his vehicle running while his fare went inside to buy shoes.

But the problem is, the bylaw's strength melts away as the heat gets stronger.

When the temperature climbs over 27 C, all idling vehicles are off the hook. Also, all service vehicles are excluded.

Eva Ligeti, with the Clean Air Partnership, an initiative created by the city, defends the city's move.

"There are other problems, this is just one attempt to start making the connection between your energy use and air pollution," she told CBC News.

Environmental group Pollution Probe agrees saying the enforcement and anti-idling blitz is a good way to get the message out.

However, the group's executive director Ken Ogilvie told CBC News Online that he hopes that the public will understand that even though drivers will not be fined for idling when the temperature hits 27 C, "it's probably more important not to idle at that temperature."