Heat-sensitive labels are special types of labels that change color or become transparent when exposed to heat. They are often used in packaging to indicate whether a product has been stored at the correct temperature. This feature helps ensure the quality and safety of items like food and pharmaceuticals. These labels work by using materials that react to temperature changes. When the temperature rises above a certain threshold, the label's appearance alters, providing a visual cue. This technology is useful in various industries, including food safety, pharmaceuticals, and shipping, helping to prevent spoilage and maintain product integrity.