As winter bears its chilly head once again, drivers across America are looking at the frost and snow on their windshields with a sense of foreboding. The outside cold quickly seeps into the cabin, which can result in a long, almost unbearably frigid drive until the engine gets hot enough to blast comfortable warm air.

For many drivers, the go-to solution for this annual problem is to let the car warm up before hitting the road. However, some states and municipalities still have laws on the books that make it illegal to heat your car before driving it. This practice can also leave your car at an increased risk of theft, and there are some notable environmental concerns for those using gas-powered vehicles.

Risk 1: You may be breaking the law

If you're planning to warm (or "idle") your car this winter, you may want to check your state's laws. According to the National Conference of State Legislatures (NCSL), nine U.S. states and the District of Columbia currently have some form of law designed to discourage vehicle idling. The states that currently have these laws in place include:

• Colorado
• Connecticut
• Delaware
• Maryland
• Massachusetts
• New Hampshire
• New Jersey
• Texas
• Vermont

According to the NCSL, these laws typically say most vehicle classes cannot idle for more than three to five minutes before driving, though limitations vary by state. An additional 14 states place idling limitations on specific vehicle classes, such as buses, state-owned vehicles and vehicles above a certain weight.

If you're not in one of the aforementioned states, you may not be out of the clear just yet. Many local municipalities have their own restrictions on idling. New York City is a perfect example. Although there's no statewide law restricting vehicle idling in New York, there's a city-wide ban on the practice in NYC. You cannot idle your car in NYC for more than three minutes. Only buses are exempt from the law.

Before you idle your vehicle, check for laws governing the practice in your area. Otherwise, you could be hit with a fine of several hundred dollars.

Risk 2: You may risk losing your car or valuables within it

Burglary and theft are common crimes in the United States. Even individuals living in rural communities experience property crimes such as grand theft auto.

Many people leave their keys in the ignition and let the car idle alone while it warms up. This provides the perfect set-up for a thief, who can easily climb in and take the car. Starting your car with a remote key can help, as the car will remain locked while it warms up.

Crime statistics don't break down how many cars are stolen while idling, but there's plenty of anecdotal evidence to verify the risk is real. For example, in early October 2019, 14 idling cars were stolen within the span of just four days in Greeley, Colorado, prompting local police to issue a warning about the issue. Police officers noted that reports of stolen vehicles tend to increase as the temperature drops.

Your car insurance company also won't be a huge fan if your car gets stolen. Most insurance policies cover theft if you have comprehensive coverage in place. However, your insurer may ask whether your keys were in the car ignition. If they were, then the insurer may not cover the incident and could even increase your premiums.

Even if your car isn't stolen, an idling vehicle may be a perfect opportunity for thieves to hop in for a second, grab as much as they can and run. Your renters insurance or homeowners insurance may cover this type of theft, but going through the claims process is rarely a fun experience.

Risk 3: You could be contributing to global climate change

The negative impact on global climate change is among the reasons many states and cities place limits on car idling. A U.S. Department of Energy report highlights the fact that car idling wastes 6 billion gallons of fuel each year.

That same DOE report also explains that idling for more than 10 seconds produces more climate-impacting carbon dioxide emissions than stopping and restarting your vehicle.

The problem is serious enough that, while some states completely ban idling, others offer financial incentives for companies to develop technologies or solutions that help limit drivers' need to idle. Fourteen states and the federal government offer a mixture of grants and business loans that either mention or have money specifically earmarked for vehicle idle reduction efforts.

New technologies may reduce key risk factors

There's a potential silver lining when it comes to the risks of car idling.

Some vehicle technologies are making it far more difficult to steal an idling car. Remote starters, for example, allow you to turn on and warm your car without having to put the key in the ignition. These cars typically won't move until the key is either in the ignition or inside the car. That's particularly the case with newer vehicles that feature a push-button starter.

Many newer cars also feature anti-theft technologies such as a remote engine lock. These can be enabled through a mobile device or by contacting the car manufacturer. Another bonus? This type of tech can save you 5%–15% off your insurance.

Electric vehicles also eliminate the risk of adding to pollution and fuel waste from vehicle idling. As electric cars use no fuel and produce no emissions, you can idle without worrying about adding excessive carbon emissions into the air.

No matter how good the technology is, some states and cities may stand firm on anti-idling laws. Even if your car produces zero emissions, you may still be at risk of violating a local or state ordinance against it.

Dropping temperatures may make it tempting to warm your car for a few minutes before you begin your drive. Although new technologies reduce some of the key risks, drivers should be aware of the potential pitfalls and risks associated with leaving your car on and unattended.

Maxime Rieman is Product Manager at ValuePenguin. Educating and assisting shoppers about financial products has been Rieman's focus, which led her to joining ValuePenguin, a consumer research and advice company based in New York. Previously, she was product marketing director at CoverWallet and launched the personal insurance team at NerdWallet.