10 Things That Are Foolish to Leave In the Car

Juggling life as a dad and husband means my car often doubles as a family hauler and occasionally, a makeshift storage space. But I’ve learned the hard way that some things just don’t belong in there.

From a rogue lighter that nearly gave us all a scare to the snack stash that turned into a science experiment, keeping the wrong items in your car can lead to more than just inconvenience—it can be downright dangerous. These are 10 things that should never find a permanent home in your car.

Canned Drinks

Leaving canned beverages in your car might sound like a convenient way to have a cold drink ready after a long day, but trust me, it’s not worth the risk. Those cans can explode under extreme heat or even freeze and burst in the cold. Cleaning up a sticky, soda-soaked interior is no joke and definitely not how you want to spend your weekend. It’s a lesson I learned the hard way, and now, I make sure to grab any cans before leaving the car.

Valuables

As a dad who’s always on the go, I can’t stress enough how important it is to keep items like your wallet, cash, important documents, and electronics out of sight when parking your car. Thieves are opportunistic, and leaving such items visible can turn your vehicle into a target. I’ve made it a habit to double-check that everything valuable is either taken with me or hidden away securely. This small step can save you a lot of trouble and ensure your possessions are safe.

Medications

Keeping medications in your car during extreme temperatures is something I’ve learned to avoid the hard way. In the summer, the heat can quickly degrade the effectiveness of your meds, and even the cold has its downsides, causing moisture that can lead to pill clumping or even bacterial growth. As a dad, making sure our family’s health isn’t compromised by something as preventable as this is a priority. I’ve found that using a cooler or an insulated bag when transporting medications keeps them safe and potent, and it’s a simple step that goes a long way.

Makeup

As someone who has had to replace melted items from my wife’s makeup kit more than once, I can tell you firsthand that leaving makeup in a hot car is a recipe for disaster. High temperatures can turn your cosmetics into a goopy mess, affecting their texture and, worse, their safety, potentially leading to skin irritation or breakouts. And it’s not just about the heat—sun exposure can degrade the quality further, fading pigments and messing with the formula.

Lighters

Keeping a lighter in your car might seem like no big deal, especially if you need to light a cigarette or start a campfire on a trip. But just like aerosol cans, lighters are bad news when left in a hot car. The heat can cause them to leak gas or even explode, which could start a fire in your vehicle. It’s a risk that’s easily avoided—just keep the lighter in your pocket or a bag instead of the glove compartment or console.

Batteries

Whether it’s for your car’s remote or an emergency flashlight, batteries are often something you just leave in the glove box and forget. However, extreme temperatures can wreak havoc on batteries. Heat can cause them to leak corrosive liquids that might damage your car’s interior, and cold temperatures can drain their power faster than usual. To keep them in good shape and ready when you need them, it’s best to store them at a moderate temperature and check them periodically.

Plastic Water Bottles in Your Car

Keeping plastic water bottles in your car might seem harmless, but it could be a health gamble. Heat and plastic are a bad combo, potentially releasing chemicals like BPA and phthalates into your water. These aren’t just fancy chemical names; they’re linked to serious health issues, including heart disease and cancer. Plus, a water bottle sitting in the car can become a breeding ground for germs over time. So, next time you park, bring that water bottle with you or opt for a safer, reusable one that can handle the heat.

Eyewear in the Car

Those handy built-in compartments in your car for sunglasses are great—while you’re driving. But once you’re out of the car, take your glasses with you. The heat can do a number on them, warping plastic frames and heating metal ones to a point where they could burn your skin. And if you’ve ever left them on the dashboard, well, that’s a recipe for disaster. The glass acts like a magnifying glass, intensifying the sunlight and potentially damaging your lenses or frames, according to experts like Susan Thomas from the American Optometric Association.

Alcohol in the Car

I’ve found that keeping any type of alcohol in the car, especially during those blazing summer days, is asking for trouble. Whether it’s disinfectant alcohol or a bottle of your preferred beverage, high temperatures can turn them into hazards. Disinfectant alcohol can expand and burst, damaging your car’s interior. And there’s nothing like the lingering smell of spirits to spoil the comfort of your vehicle.

Aerosol Cans

Here’s a bit of advice from one dad to another: be wary of leaving aerosol cans in your car. These containers are under constant pressure and filled with flammable materials that can become dangerously volatile in the heat. I’ve learned that the risk of them exploding isn’t worth taking. If there’s no avoiding transporting them, I make sure they’re kept in a cool, shaded spot in the vehicle.