CAR thieves in West Yorkshire are cashing in on the cold snap by "frosting".
Drivers who leave their cars unattended with engines running to defrost outside their homes are falling foul of "frost jackals" on the lookout for easy targets.
Home Office figures show that four out of 10 of the 375,000 cars stolen in the UK each year are taken from outside their owners' homes.
Also, the number of such thefts rises significantly in cold spells.
Police backed security advice about the risks.
A spokesman said: "Immobilisers and alarms do go some way to deterring opportunist thieves.
"But never leave your car unattended and with the engine running - even in your drive or outside your home," he added.