8 Things You Should Never Leave in A Hot Car

A guide for eight things you should never leave in a hot car. 8 Things You Should Never Leave in A Hot Car drivrzone.com

We forget all kind of things on the car, but with summer already here, it’s important to be cautious. Vehicles can reach high temperatures in short periods of time if left exposed under the bare sun. The bad thing about this is that many things can be ruined by the sun, or even worse, ruin your car.

This article assumes you’re cautious enough to never leave your pets, children, or grandparents alone in a hot car. We’ll target those items that are the most common and seem the most harmless to your car. Included are some things that won’t damage your car, but will be ruined by heat or direct sunlight.

The best solution is prevention. Don’t use your vehicle as a storage room, only save what’s necessary to have inside the car. During this summer, run a quick search through your car before leaving to ensure you’re not forgetting any of these items inside.


Thing to Never Leave in A hot car - batteries

You’ve probably seen labels all around batteries telling you not to expose them to heat. The thing is that, in most cases, the batteries are inside some device and we may forget they’re even there.

Unfortunately, the device is unlikely to protect the batteries from the sun. In the case of Li-ion batteries (your good ‘ole AA/AAA remote control battery), exposure to heat will lead to internal short circuit and explosion. They’ll literally set on fire inside your car if heated enough.

In the case you’re lucky and they don’t explode, the exposure can still make the battery fail and leak some of its acids. Needless to say, the battery acid can easily mess up whatever device it powers.


How many times haven’t we left the phone on the car? Whether it’s on purpose or not, that can’t happen this summer. Most electronic devices are delicate regarding sun and heat exposure, including tablets, smartphones, gaming consoles, and so on.

This is because these devices count with many components and liquids that are degraded by heat. Additionally, all electronics contain a battery, which includes this in our first point. You’re not only running the risk of the electronic device but the battery as well.

Anything can happen from your LED screen liquid leaking to the battery suffering a terminating failure.


Medicines are an extremely delicate topic. You’ll often find very specific instructions on how to store the medicine in a safe manner. None of them will support the idea of leaving it in a hot car.

Each medicine will have its own reaction to heat, but in general, these reactions are never good. After some exposure, they may simply lose their active component and effectiveness. In more severe cases, the chemical components may go bad and generate unpleasant side effects upon consumption.

Plastic Containers

There is a lot of controversy regarding plastic bottles and exposure to heat. Some myths point to the bottles or containers leaking some harmful compounds on food and drinks. This is not true. There is, however, a chemical called bisphenol A (BPA) which is released when the containers are heated.

Released in small quantities, this reaction is believed by some scientists to have an impact on babies. Ideally, baby bottles should be BPA free, as demanded in the EU. Though, reliable sources explained that BPA is a legal compound, with no proven impact on the health of a human adult.


There are two good reasons why you should never leave glasses in a hot car. First, any plastic parts will be exposed to a degree of heat that may affect its shape or integrity. The smaller the component, the easier it will melt.

A bigger problem is the lenses. If unfortunately left directly under the sun, the glasses will quickly act as a magnifying glass along with the windshield. There is a huge list of scenarios in which this can end terribly wrong.

Aside from glasses, avoid leaving any object that may act as a magnifying glass in general

Fresh FoodThing to Never Leave in A hot car - fresh food

Many of us keep an emergency snack on our vehicle. In normal circumstances, keeping boxed food in the car for the day won’t cause any harm. However, if you went shopping for groceries, the car is no place to leave them sitting this summer. Heat, moisture, and nutrients make the perfect environment for bacteria.

In the temperatures of a hot car in summer, bacteria will multiply much faster. In a period of 12 hours, an average food bacterium may easily nest 17 million of them. Fresh meats and fruits will decompose gradually, creating even further bacteria, dangerous ones.

Canned products

As a general rule, you never want to leave cans in a hot car. Some specific products may be fine if you’re sure there’s nothing dangerous in its components. The thing is that it only takes one unfortunate compound or gas to make a huge mess inside your car.

Depending on what they are, some chemicals may start to decompose, or some cause an explosion. The latter is the case of soda cans, which contain gasses that can make the can explode. Potentially heat-sensible compounds and gases may lie within quotidian things that you may leave in your car.


Some smokers make the mistake of carrying a spare lighter on their vehicle. Under normal climatic circumstances, it’s still unsafe, but not a major hazard. On a hot car during summer, though, a lighter quickly becomes dangerous.

The flammable gas within the lighter will likely make it explode if exposed to high temperatures. It will leave a cloud of flammable gas that will react to any unfortunate spark. Additionally, the gasses released are not safe to breathe and will remain trapped in your car.

Last Thoughts

It’s important to remember that vehicles will heat up even if the four windows are completely rolled down. This is because they contain a lot of metal components that absorb sunlight and heat up considerably fast.

All objects in this list will be affected by heat – not necessarily direct sunlight. Placing them directly under the sun will make it worse, but, unless specifically protected, no part of inside car is safe from heat. These eight items are still in danger if the car has the windows down and away from the sun.

Take some free time and search your car thoroughly. You’d be surprised by how many of these things may have been accidentally forgotten there. We know you’ll try to get the spots with a shade this summer, but still, create the habit of making a quick search before leaving your car parked.



  1. BBC UK – Can plastic bottles cause cancer?
  2. American Cancer Society – Rumors and Myths About Plastic Water Bottles
  3. Eat Out Well – Will Food Sitting in A Hot Car Make Me Sick?