A thermos flask is a container designed to keep liquids hot or cold for extended periods. It typically consists of two layers of material, often glass or stainless steel, with a vacuum in between that minimizes heat transfer. This design helps maintain the temperature of beverages like coffee, tea, or soup. Thermos flasks are popular for outdoor activities, travel, and daily use. They come in various sizes and styles, making them convenient for carrying drinks. Many people use them to enjoy their favorite beverages at the right temperature, whether at work, school, or during hiking adventures.