Leaving a clear, curved water bottle in direct sunlight inside a parked car can accidentally act as a lens, concentrating light rays onto nearby surfaces.If that focused beam hits dark upholstery, paper, or plastic, it can generate intense heat and potentially spark a small fire.he hazard applies to both glass and plastic containers, as the primary risk stems from how sunlight is redirected rather than the material itself.To eliminate this unusual risk entirely, simply take your bottle with you or store it in a shaded area out of direct light.
