Are Polar Tech cold packs considered phase change materials (PCMs)?

Yes. Polar Tech cold packs are considered phase change materials (PCMs). They contain water-based gel that changes phase from liquid to frozen and back to liquid again. As the product melts from solid to liquid, it absorbs heat and helps maintain the desired temperature inside the shipping container.

While our cold packs are not classified as “specialty” PCMs with engineered non-0°C phase change points, even a simple water-based gel pack or water in a bag is considered a PCM because it undergoes a phase change.