It's cold outside and that means car thefts are on the rise. The Nampa Police Department says it's a crime of opportunity and completely preventable.

Four people had their vehicles stolen Thursday morning while they were warming up their cars and left them unlocked and unattended. In total, eight cars have been stolen since the beginning of the year.

Sgt. Tim Riha says this crime happens every year around this time, but it's easy to avoid.

"I think they (suspects) do drive around and look for this but other ones could just be crimes of opportunity," said Riha. "They're walking by and are tired of walking in the cold so they're going to take that warm car sitting over there."

Riha says if you want to warm up your car lock it up and use a spare key to get back inside. You can also get an automatic car starter. The simplest option, he says, is bundling up when you go somewhere so you can handle the shock of a chilly car.