12 Items You Should Never Keep in Your Car

Your car might seem like a convenient storage space, but leaving certain items inside, especially during extreme weather, can be dangerous, costly, or even illegal. From summer heatwaves to icy winters, vehicles are exposed to temperature extremes that can turn harmless objects into potential hazards or render them useless.

Whether you’re heading out for errands or parking for the day, here are 12 items you should never leave in your car, for both safety and practical reasons.

1. Electronics (Laptops, Phones, Tablets)
Electronics are highly sensitive to temperature fluctuations. In extreme heat, internal components can melt or warp, and in cold temperatures, batteries may drain rapidly or permanently lose capacity. Plus, leaving valuable electronics in plain sight increases your risk of theft.

2. Aerosol Cans (Hairspray, Spray Paint, Deodorant)
Aerosol cans are pressurized and can explode when exposed to high heat, typically anything over 120°F (49°C). That means your car on a hot day can turn into a literal pressure cooker. Even in freezing weather, these cans can malfunction or burst due to expansion and contraction of gases inside.

3. Medications
Many prescription and over-the-counter medications must be stored at controlled room temperatures, usually between 68°F and 77°F (20°C to 25°C). Leaving them in a hot or freezing car can cause chemical degradation, making them less effective or even harmful.

4. Plastic Water Bottles
While it’s tempting to keep water handy, plastic bottles left in hot cars can leach chemicals like BPA into the water. In freezing temperatures, water can expand and cause bottles to burst or crack, creating a mess, or worse, mold and mildew if unnoticed.

5. Perishable Food
Leaving groceries, snacks, or takeout food in the car can lead to rapid spoilage, especially in the summer. Harmful bacteria multiply quickly in warm environments, turning your lunch into a food poisoning risk. In winter, certain items may freeze, ruining texture and taste.

6. Batteries (AA, AAA, Lithium-ion)
Like electronics, batteries can suffer in extreme temperatures. Heat can cause battery fluid to leak or even explode, while cold temperatures drastically reduce battery performance and lifespan. This includes power banks and spare car batteries.

7. Important Documents (Passports, IDs, Insurance Papers)
Documents left in a car are vulnerable to theft and identity fraud. Heat and sunlight can also fade ink or damage paper over time. If you must transport important documents, keep them with you rather than locked inside a car, even in the glove compartment.

8. Sunscreen and Makeup
These personal care items often contain active ingredients that degrade when exposed to heat. Sunscreen, for example, can lose its effectiveness, leaving you vulnerable to UV rays. Makeup can melt, separate, or spoil, especially in high temperatures.

9. Pets and Children
This should go without saying, but unfortunately, it bears repeating: never leave pets or children in a parked car, even for a few minutes. Temperatures inside a vehicle can rise or fall dramatically within minutes, leading to heatstroke, hypothermia, or death.

10. Canned or Carbonated Beverages
Cans of soda or beer can explode in both hot and cold conditions. Heat increases internal pressure, while freezing temperatures cause the liquid to expand, either way, the result is usually a sticky mess and potential damage to your car’s interior.

11. Eyeglasses and Sunglasses
Plastic or resin lenses can warp or crack in high heat, and metal frames may become dangerously hot to the touch. In extreme cold, coatings may crack or peel. Expensive prescription glasses can also be a target for theft.

12. Credit Cards and Bank Cards
The magnetic strip and chip on cards can become damaged by heat, rendering them unreadable. Also, just like documents, these are vulnerable to theft and fraud if someone breaks into your car.

Final Thoughts
Your car isn’t a climate-controlled storage unit. While it’s tempting to stash items for convenience, it’s important to consider how temperature and time can affect them. A little planning, like bringing a small bag for valuables, or using an insulated cooler for food, can go a long way in protecting your belongings, your safety, and even your wallet.

When in doubt, take it with you. It’s always better to be cautious than to return to a melted laptop, spoiled lunch, or worse.