HARRISBURG, Pa. (WHTM) — When the temperatures start dipping, preventable auto thefts go on the rise.

That’s because many people leave their car unlocked, unattended and running while it warms up.

“Thieves take advantage of the situation. An unattended vehicle that’s unlocked is a quick opportunity for them to get in the vehicle and take it,” state police Trooper Brent Miller said.

It’s called “puffing” when a running car is unlocked and unwatched. The term was coined in cold weather states, but police say you can “puff” your car without it being stolen.

“If you need to start your vehicle to defrost it, be out there with it. Start it up, bundle up. It is cold, but stand there with your vehicle,” Miller said.

Puffing is also illegal depending on where you are.

“It is illegal to leave your vehicle unattended and idling on a public roadway. Obviously, if it is on your private property, that’s a different story,” Miller said.