A warning from police to drivers could help reduce car thefts as the temperatures drop.
"Puffing" is when a driver leaves their car on and unattended when warming or cooling it off.
It's actually illegal and you can get a ticket for it.
According to detectives, thieves are most likely to target puffing cars in driveways or store parking lots.
The practice is more common in cold weather months when people are trying to warm up their cars before hitting the road.