In one case, a firefighter in Idaho discovered his car seat smoldering after sunlight, refracted by a water bottle, focused onto the upholstery.
To prevent such incidents, firefighters advise against leaving water bottles in vehicles, especially in direct sunlight.
If bottles must be stored in cars, it’s safer to keep them in shaded areas or to use opaque containers. Public awareness campaigns are being launched to spread this message and help reduce the risk of vehicle fires.