PCMs are substances that absorb and release thermal energy during melting and freezing. In the case of our lightweight and flexible Cooling Packs, the PCM slowly absorbs your body heat over time to keep you cool and comfortable, even in humid environments.

Questions about our vests or shipping? Reach out to the ThermApparel team toll-free at 855-232-7233, write to us through our website’s contact form or chat with us via live chat. We always respond because, otherwise, that wouldn't be cool.