With overbearing heat mounting in SE Michigan, this is a friendly reminder that leaving your water bottles in your car on a hot day can start a fire inside your car – if the conditions are right.

On a hot, summer day – like we’re experiencing right now – a full plastic bottle of water can act like a lens, focusing light into a high-energy beam that’s intense enough to start a fire. Much like holding a magnifying glass on a sunny day can start a fire, the filled bottle of water does the same thing.

In 2017, a power company in Idaho shared a video of a water bottle burning two holes into a seat of a car. A technician was sitting in his truck when he noticed his leather seat was starting to smoke.