As temperatures drop, some drivers may want to warm up the car ahead of time for their morning commutes, but people should avoid the temptation if they want their cars to be there when they come back outside.
Car thefts are a constant problem year-round, but law enforcement agencies see a significant uptick during the winter, mostly because grand larceny becomes as easy as opening a car door.
"These are mostly thefts of opportunity," said Rob Simmons, spokesman for the Chattanooga Police Department. "In a desire to have the instant gratification of a warmed vehicle during their commutes, many people start their vehicles in their driveways or leave their vehicles running while visiting a store."
"Car thieves are counting on these bad habits, and yet it remains to be the most completely preventable crime in our city," Simmons said.
Chattanooga saw 977 vehicles stolen in all of 2016. The pace picked up this year, with 1,094 stolen as of Oct. 15. More than 350 of those cars were stolen with the keys inside, and the number might be higher since some people are too embarrassed to tell police they left the car running.
Statewide, the Tennessee Bureau of Investigation said 15,609 car thefts were reported to them by local law enforcement agencies in 2016. In those cases that were solved, 2,244 adults and 428 juveniles were arrested.
The problems associated with car thefts can go beyond the loss of a vehicle — unwary victims frequently open themselves up to even greater trouble.
"Leaving your keys in the vehicle may not end with just your car being stolen but your home being burglarized as well," Simmons said.
"Thieves will leave your car keys and remove your house keys or garage opener. Once you have left for work, a thief with open access to your home has hit the jackpot."
Oddly, the frequency of car thefts is increasing despite increased industry standards for security systems that should be pushing the trend in the other direction.
"We have all seen movies where the thief just connects the red and green wire under the dash and starts the car. Modern vehicles have immobilizing systems which prevent a vehicle from starting unless the key or key fob is present and recognized by the computer in the vehicle," Simmons said.
"Even though it is extremely difficult to steal a car these days, we are still experiencing a record number of auto thefts due to our desire to have a warm car in the morning. These victims are enabling these thefts by presenting easy opportunities to those with deplorable intentions."
Matt Lea, a spokesman for the Hamilton County Sheriff's Office, said the department doesn't typically see an uptick in vehicle thefts during winter, but echoed Simmons' cautions about preventative measures.
"This year, we have seen an abnormally high level of vehicle thefts, especially during the summer months. Most of these thefts can be attributed to owners leaving their vehicles unlocked over night with/without valuables left inside," Lea wrote in an email.
"The [sheriff's office] recommends to all motorists to never leave their vehicles unlocked when not in use and to never leave any valuables, computer devices, money, or firearms inside their vehicle when they are not physically with the vehicle. Motorists should always check their vehicles to ensure they are properly locked at all times."
Contact staff writer Emmett Gienapp at email@example.com or 423-757-6731. Follow him on Twitter @emmettgienapp.