Certain items, such as laptops, cameras, and overnight bags, should never be left in your car — that is, if you ever want to see them again. In addition to the risk of theft, there’s also the danger of heat and damage from the sun. Extreme temperatures can ruin sensitive items, while the UV rays of direct sunlight can warp, fade, or weaken materials even faster. Even on a comfortable 73-degree day, a car parked in direct sunlight can reach an internal temperature of 120°F within an hour.
However, it’s not just electronics that react badly to “hot box” conditions. Do you know what happens to aerosol cans in a hot car? Or soda, sunscreen, or food? Did you know that a lighter can explode in a hot car? Many common household items can be damaged — or worse — become a danger if exposed to extreme heat. And the danger to children and pets in a hot car must never be risked.
Read on to learn the 10 items you should never leave in a hot car.
1. Children, Pets, and Plants
It seems obvious, but it bears repeating — living beings must never be left in a locked car. The rapidly increasing heat inside the car can prove deadly to older adults, people who are sick, children, pets, and even plants. Cracking a window is not enough to protect them. Children and pets are at risk of heat stroke and dehydration well before death occurs, and it can happen in just minutes. Within the first 10-15 minutes, the car’s interior temperature can rise by 20°F or more.
Never, ever — ever — leave a child or pet in your car. Even for “just a minute.” No matter how good your intentions, other people or events can delay your return, and the results can be tragic. Of course, you know this. Everyone does, right? Yet every year, an average of 37 children and hundreds of pets die due to heatstroke while locked in a car.
2. Aerosol Cans
Most aerosol cans should be stored in a ventilated space at temperatures under 120°F. Remember that a car’s interior soars to 120°F when the day is just a mild 73°F. In many parts of the country, the mercury can reach the 90s and 100s, so internal car temps will be even higher. The contents of aerosol cans, such as those containing hairspray, sunblock, or spray paint, are under pressure and will expand in the heat.
Aerosol cans in a hot car are flammable and can explode and cause a fire. This can prove dangerous or even deadly to anyone in the vehicle at the time. Clear your car of aerosol cans as soon as you get home so they don’t get forgotten.
3. Medication
As you’re most likely aware, many medications must be stored at room temperature to remain fully effective. So, leaving them in a hot car for any length of time is not optimal, as the drug’s potency can decrease. Also, creams and ointments can melt. Try to plan your pharmacy pickup at the end of your errand run, just before heading home.
4. Sunscreen
Like medication, sunscreen does not do well when left in a hot vehicle. Extreme temperatures can render the formula less effective and cause the ingredients to separate and potentially leak. Will sunscreen explode in a hot car? If it’s an aerosol or spray-on sunscreen, it sure can. If it is not a spray, the sunscreen bottle may still burst.
If you like to keep sunscreen on hand in your car, but don’t want an oily mess all over the interior, try a sunscreen formulated with mineral powder that comes with a brush. That way, you avoid messy spills while still protecting your skin from the sun’s harmful rays.
5. Hand Sanitizer
According to stories on the internet, hand sanitizer can explode if left in a hot car. While alcohol-based formulas could explode or ignite when exposed to flames, it is unlikely to happen due to the high temps inside a car. Several studies have shown that the maximum temperature in a vehicle left in direct sunlight for an hour would reach 160°F.
The alcohol in the sanitizer would have to reach 600°F for it to spontaneously combust. However, as with other materials, heat can reduce or destroy the product’s effectiveness.
6. Batteries and Power Banks
Batteries and power banks (also called portable chargers) should never be left in a hot car. High temperatures can cause batteries to swell, leak corrosive material, or even catch fire. Lithium-ion batteries, commonly found in phones, laptops, portable chargers, and power tools, are particularly susceptible to heat damage and pose a fire risk if overheated. However, even a pack of AA or AAA batteries can leak when exposed to temperatures over 100°F, which can happen fast in a parked car. Always take the batteries with you when you leave your car.
7. Electronic Devices
Electronic devices like phones, laptops, tablets, and e-readers should not be left in a hot car either as they can suffer serious damage. High temperatures can warp plastic casings, crack screens, and damage internal components like batteries, processors, and circuit boards. Even when the device still works afterward, extreme heat can shorten the lifespan of electronic devices or cause problems that show up later. To protect your electronics — and the valuable data they contain — take them with you.
8. Food
Food can quickly spoil when subjected to extreme heat. “Meltables” like chocolate and ice cream come to mind, but any type of perishable food will be unfit for consumption if left in the car for any length of time. It’s even a bad idea to leave bread in a hot car because the heat accelerates the bread becoming stale and growing mold.
As with medication pick up, head straight home after the grocery run. Planning a picnic? Pack your goodies in a cool bag and remove them immediately from the car after you park.
9. Drinks
Your favorite beverages are also susceptible. No one wants to drink warm water, soda, beer, or wine on a hot day, so place bottles or cans in an ice-filled cooler whenever possible.
Will soda explode in a hot car? High heat does cause the carbonation pressure to build up. An explosion is unlikely, but it can happen if the can’s seal is weak. More often, the pressure deforms the can or makes the soda spray or fizz when it’s opened.
If you leave soda in a hot car, it’s generally safe to drink, especially if it’s in a can. Plastic water bottles, however, present a concern: heat can cause tiny amounts of chemicals like BPA or antimony in the plastic to leach into the drink. While drinking hot soda once isn’t likely to cause immediate harm, it’s smart not to make a habit of it.
10. Eye Glasses
If you need to wear glasses to see clearly, they will hopefully be on your face when you get out of the car. But spare sets and, of course, sunglasses are often left behind. If glasses are left in the car for any length of time, they’ll be too hot to wear, and you run the risk of the sun warping the frames. Eyeglasses are another thing you should not leave in a hot car. Store any spares in a case and consider investing in a chain to keep sunglasses around your neck.
Bottom line: It’s best not to leave anything in your car on hot days, but sometimes you have no choice. If that’s the case, try to mitigate the heat by parking in the shade or following our safety tips for storing items in a hot car.
Safety Tips for Storing Items in Hot Weather
When parking your car in warm weather, a few simple strategies can help protect your belongings from heat and sunlight damage:
- Use insulated storage bags or thermal containers to keep food, drinks, and temperature-sensitive items cooler for longer.
- Keep windows slightly open (if it’s safe) to let trapped heat escape and help lower the interior temperature. Please note: a cracked window is not enough to allow you to leave a child, pet, or vulnerable adult in a parked car, even for a short time.
- Block sunlight and reduce heat by investing in a sunshade for your windshield. It slows the buildup of heat inside the cabin.
- Store items in the trunk or under seats to keep them out of direct sunlight, which can quickly cause warping, fading, and even permanent damage.
Taking a few extra precautions with the things you can’t leave in a hot car can help you protect your belongings — and your peace of mind — on hot days. Why not take the same approach with your car insurance? Contact a friendly Wawanesa agent today to review your coverage and make sure you’re fully protected.
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