Winter has placed a firm grip on Central Indiana, which means many motorists are starting their cars before they drive to work.

Police want you to know that those unattended vehicles, often left running with the keys inside, are juicy targets for thieves.

“Leaving a vehicle running unattended is a very dangerous thing to do and can result in an even greater tragedy,” Lawrence Police Capt. Gary Woodruff said.

Since Jan. 1, records show, there have been at least 64 reports of vehicles taken while they were left running and unattended in Marion County.

Last week, someone nabbed a car that was left running with a 4-year-old boy inside while his mother went into a Phillips 66 station on the east side. The thief did not go far. Police found the car behind the gas station and reunited the child with his mother.

On Tuesday, Lawrence police arrested two 15-year-old boys caught inside a vehicle that had been reported stolen after the victim left it running.

Lawrence police have reason to be more sensitive to the issue than other departments.

In 2005, two 15-year-old boys were in a stolen van that led police on a chase at speeds topping 100 mph. The van launched after hitting some railroad tracks and crashed into a squad car, killing Lawrence police officer Craig Herbert.

That van, stolen the night before, had been left running and unattended.

Although police advise drivers to stay inside their cars while warming the engine, Johnson County Sheriff Doug Cox said he knows most people won’t listen.

“They’re still going to do it, no matter what I say,” Cox said.

The Johnson County Sheriff’s Office received reports of three vehicles stolen while left idling in the past month. Two were taken from driveways, one from outside a business.

Cox urges residents who insist on warming their vehicles and going back inside to at least keep them off driveways.

“When you have garage space, use it,” Cox said. “If you have to clean out the garage, do so and get your vehicle in because there’s just too much nonsense going on.”

Call IndyStar reporter Vic Ryckaert at (317) 444-2701. Follow him on Twitter: @vicryc.