Water
As summer temperatures climb, it’s easy to toss things in the car and forget about them. Whether you’re running errands, heading to the beach, or rushing between activities, most of us have left something behind in the back seat at one point or another.

But while it may seem harmless, some everyday items can become surprisingly dangerous when they’re left inside a hot vehicle. Even something as common as a plastic water bottle can pose unexpected risks.

It’s easy to let jackets, bags, shopping, and even a little clutter pile up in the car. After a long day, bringing everything inside often feels like more effort than it’s worth. But treating your car like a storage unit isn’t a habit you want to get into—especially during the hottest months of the year.

Most people know never to leave children or pets in a parked car. But there are plenty of other items that can be damaged by the heat – or even become safety hazards. According to Erie Insurance, there are several things you should never leave in your car.

Products like spray paint, hairspray, and household cleaners can become dangerous in extreme heat. As temperatures rise, the pressure inside the can builds, increasing the risk of leaks, ruptures, or even explosions.

Disposable lighters may seem harmless, but they can leak or explode when exposed to high temperatures, creating a potential fire hazard inside your vehicle.

Never leave these things in your car
Leaving canned sodas or other beverages in a hot car isn’t a good idea either. If the can overheats, it can burst, leaving behind a sticky mess that’s difficult to clean.

Loose batteries are also sensitive to heat. High temperatures can cause them to leak corrosive chemicals, which may damage your car’s interior or any nearby belongings.

A forgotten plastic water bottle may not seem like a big deal, but prolonged exposure to heat can cause chemicals from the plastic to leach into the water. While experts continue to study the long-term effects, it’s generally best to avoid drinking water that has been sitting in a hot car for hours.

Many people keep medications in their car for convenience, but it’s not recommended. Heat and frequent temperature changes can reduce the effectiveness of certain medications, making them less reliable when you need them most.