Ideal for lunch boxes. Keeps food both cold and fresh. Reusable. Freeze and use. Ice-Pak™ bottles are filled with our premium water-based, non-toxic Perma-Gel. With a freezing/melting point of 0°C, these packs are used to transport temperature- sensitive items safely and more efficiently than ice. The durable HDPE plastic makes them reusable and provides excellent protection in cold chain applications.