The Humane Society advises you to slap the hood of your car or honk the horn before starting the engine on cold days to startle any animal that may have crawled underneath seeking shelter and warmth.

And just as you wouldn't leave an animal inside a hot car in summer, don't leave your pets in your car in winter.

Finally, if you live in a warm climate, don't think you're off the hook. Even in places such as Florida, winter temperatures, normally in the mid- to high 70s, can plummet 30 degrees or more in the course of a day.

"Don't leave pets outside if you're going to be gone for several hours," says South Florida veterinarian Dr. Amy Balko. "Bring them in the house or make sure they have access to shelter if the temperature suddenly drops.

"All pet experts agree on one thing -- if it's too cold for you to go outside for prolonged periods of time, then it's too cold for your pets.