PEOPLE have been urged to lock their doors when they go out to take their dogs for quick walks.
The warning comes after a sneak-in burglar slipped into a Huddersfield home to steal after the victim had taken the family pet out early one morning.
Pc Dave McSweeney, of Huddersfield police, said: "Opportunist thieves are around at all times of the day or night - even first thing in the morning.
"The golden rule is keep your doors locked at all times - even when you are at home or if you've nipped out for a few minutes to post a letter or visit the corner shop."
Opportunist thieves were just waiting for a chance to take car keys from inside homes.
And he urged people not to leave their cars running unattended on icy mornings outside their homes while the windows are defrosting.
"We had a spate of thieves jumping into cars left running with the keys in the ignition and driving off during a cold snap last year," said Pc McSweeney.
"Drivers will discover only too late that their insurance policies may well not cover them for these kind of thefts."