A number of drivers north of Toronto learned the cold truth about what might happen when a vehicle is left idling, unattended, in a driveway.

Police say they received five reports of warm-up vehicle thefts Tuesday morning. The robberies happened in Richmond Hill and Vaughan, between 6:30 a.m. and 8:30 a.m. Police say the stolen vehicles were unlocked and idling on residential driveways at the time.

One of the victims, Rhoda Cole, says she asked her granddaughter to warm up her vehicle.

"My car was parked right out here, outside the garage door," Cole told CTV Toronto. "I said I would be out in five. She left, I came out, ready for work and no car."

In another incident that was caught on a security surveillance camera, the suspects are in seen driving a black SUV down a residential street.

When it appears the suspects have noticed a vehicle left unattended in a driveway, the SUV makes a U-turn and stops in front of the driveway. A suspect then exits the SUV, casually walks up the driveway, before hopping into the stolen vehicle and drives off.

Police say they are unsure whether one group of suspects is responsible for all the warm-up thefts.

According to police, the following vehicles were taken on Tuesday:

A Honda CRV was stolen from a driveway on Valleymede Drive in Richmond Hill. It was reported stolen at approximately 6:30 a.m.

Another Honda CRV was stolen from a driveway on Avenue Road in Richmond Hill. The theft was reported at approximately 7:30 a.m.

Approximately 10 minutes later, a BMW 325i was reported stolen from a driveway on Chart Avenue in Vaughan

Shortly after 8 a.m., a Toyota Camry was stolen from a driveway on Wycliffe Avenue in Vaughan

And at approximately 8:30 a.m., a third Honda CRV was reported stolen from a driveway on Matthew Drive in Vaughan

With a report from CTV Toronto's Collin D'Mello