COLORADO SPRINGS, Colo. - Colorado Springs and Fountain police are reminding drivers that a state law makes the practice of "puffing" illegal.
Puffing is when people start their vehicles -- and briefly leave them unattended -- to warm them on cold days.
Thieves can target those vehicles, break into them and steal them while they're parked in driveways, garages and convenience store parking lots.
Colorado Springs police said 96 of the city's 1,761 vehicles stolen through mid-October were puffing.
"It's clearly a concern," said Lt. Howard Black. "There's a state law against it but we don't enforce it much because of limited manpower and the fact that it's preventable."
Black was unable to say how many citations have been issued by police.
Fountain police have yet to cite a driver for puffing, choosing to follow the Colorado Springs policy of emphasizing warnings and education over citations.
Lt. Tommy Coates said police may toughen enforcement if the number of stolen vehicles continues to rise.
"We had a situation down here where some vehicles were stolen from a puffing incident," he said. "They were involved in a pursuit with our officers that led to a crash. It was later determined those vehicles were involved in a ring of thefts."
The fine for puffing is as much as $100 if you're ticketed.
An exception to the law is vehicle owners who have automatic start keys which can lock a vehicle while it's still running.
"Some puffing vehicles are stolen by breaking into them," Coates said. "In others, the keys are left inside and the doors are unlocked. With a (remote) start key, it forces a thief to actually break into a vehicle and that's not as easy an opportunity."
Many drivers remain unfamiliar with the puffing phenomenon.
"I didn't know about it," Casey Klein said. "I'll be aware of it from now on. I don't want my car stolen."