Never leave plastic drink bottles sitting in a hot car, especially for hours or days. Temperatures inside a parked car can rise dramatically, and prolonged heat can cause chemicals from some plastics to migrate into the water. Heat can also cause the plastic to break down more quickly, potentially affecting the taste and quality of the drink. If the bottle is disposable and has been sitting in extreme heat, it’s safer to replace it rather than drink from it.
There’s also a fire risk with clear plastic water bottles. When sunlight passes through the water-filled bottle, it can act like a magnifying lens and concentrate sunlight onto a small area, potentially scorching or igniting nearby materials. This is especially concerning when a bottle is left on a seat or near other flammable materials. The safest choice is to take your drinks with you when you leave your car.
