Temperatures are set to plunge as low as minus two degrees Celsius in parts of Yorkshire this week.
But police chiefs have previously warned motorists NOT to leave vehicles unattended with the engine running while de-icing the windscreen - after a spate of thefts in the last few years.
Vehicles have been driven off by thieves who struck while motorists were keeping warm in their homes while their cars were left running outside to defrost after temperatures plummeted.
South Yorkshire Police and West Yorkshire Police have previously said unattended cars with their engines running were "enticing thieves".
SYP Roads Policing Inspector Craig Clifton said: "It may be tempting to leave your vehicle unattended allowing it to defrost before starting your journey but this makes the car vulnerable to being stolen, particularly with exhaust fumes coming from standing vehicles in the cold weather making these vehicles more identifiable.
"You don't only run the risk of your vehicle being stolen but you may also loose the right to make an insurance claim because leaving the keys in the ignition could invalidate your insurance.
"Plan your journey with extra time to safely defrost your vehicle while you are there with it."