If you find yourself doubting you could own a hybrid vehicle as you scrape off your windshield on a cold, dark winter morning, you have nothing to worry about.

Hybrid vehicles are actually designed to operate in the same range of conditions and temperatures as conventional vehicles, according to Hybridcars.com .

While all cars see their fuel economy fall as the temperature drops, hybrids usually aren't any worse, and their nickel metal hydride (NiMH) batteries perform much as traditional lead acid batteries do.

For example, Honda's specifications indicate that its Integrated Motor Assist system will operate at temperatures as low as minus-22 degrees.

Both Toyota and Honda claim the batteries in their hybrid vehicles are designed to last the life of the vehicle.

Michalis Kotzakolios, who has written several articles on hybrids for FirstKnowThis.com, points out that the thermal management systems used in hybrid car batteries keep them from experiencing performance issues from cold temperatures.

"Although there is a slight loss in battery capability while the hybrid car batteries reach operating temperature, this slight loss is undetectable in full hybrids such as the Prius," Kotzakolios said.

Hybridcars.com did report a Prius in Barrow, Alaska, suffered a frozen and damaged battery pack at minus-56 degrees, but it's doubtful a traditional battery would have performed much better in that temperature.

The Electric Auto Association says the perception that hybrids perform worse in colder temperatures is true, but that also applies to all vehicles. And hybrids still have an internal-combustion engine.

Since the temperature outside is lower, the engine's fluids takes longer to warm up, which means it takes longer for a car to run at its most optimum level, which means fuel economy will suffer.

Tire pressure also falls during cold, winter months, sapping fuel economy. Cold weather can also affect hybrids because running the defroster will keep the hybrid from shutting down the gas engine when a car is stopped at a light.

What About Heat?

And when it comes to the opposite extreme, hybrid owners have little to worry about as well.

Master hybrid technician Craig Van Batenburg, who runs the Automotive Career Development Center in Worcester, Mass., said NiMH batteries can take heat up to 140 degrees.

"It just doesn't get that hot," he said. "The air cooling works fine."

If that's not enough, advances in hybrid technology are working to ensure there are no problems, no matter what temperature a vehicle is operated at.

Companies are also working to ensure future hybrid models contain less expensive and more efficient lithium-based batteries that will work even better at colder temperatures.

The 2010 model of the Ford Fusion hybrid will feature a NiMH battery that is lighter and produces 20 percent more power than the company’s Escape hybrid. The battery can also tolerate more extreme temperatures than before.

"It's not just one thing, but thousands," said Praveen Cherian, program leader for the Fusion Hybrid. "We've optimized the heck out of that vehicle, it's individual components."