Is leaving a water bottle in a hot car dangerous? What about your toothpaste and toothbrush?
While you’re cooling off, your car’s indoor temperature can rise to 160 degrees in just minutes. And that heat causes dental items to sweat. As a rule, don’t leave these 3 items in a hot car:
Bottled Water
Plastic water bottles contain low levels of bisphenol A (BPA). Though the FDA has deemed the amount of BPA safe, the levels skyrocket from safe to dangerous after being left in extreme heat. This includes bottled water bought in bulk from the store. Enlist an assistant to help haul the water out of your trunk and into your fridge. When we’re thirsty, we’re desperate—sometimes desperate enough to drink from the bottle you found rolling around on your floorboard. Keep H2O indoors or buy a BPA-free bottle instead.
Toothpaste
Thankfully with toothpaste, chemicals aren’t a concern but quality can be. Hot temps can cause ingredient separation and a melted mess. Brands made with natural ingredients are more susceptible to melting. And the mint flavoring in your favorite tube may start to disintegrate, leaving you with less-than-fresh breath.
Toothbrush
If you keep your brush in your bag (next to your lipstick and emergency crayons), other items can melt on and around your toothbrush. Toothbrushes are a breeding ground for bacteria, and the warmth and humidity created by a wet brush breed germs. So it’s best to let your backup brush breathe. Safely store it in a clean container out of the sun and in another location—your desk drawer, for example.
Make a conscious choice to keep products indoors when the temps rise. But if you must leave them in the car, try your best to park in the shade.
Editors Note: This post was originally published June 2018. The content was revised and updated November 2024.
