ExtremeMist™ Personal Cooling System (PCS) keeps you cool when it’s hot out. Great for hiking, running and cycling, it retrofits to almost any hydration backpack and allows you to "drink and mist" from the same reservoir! Or purchase our ExtremeMist™ vest/pack with the PCS already installed. "Just Add Water!" The PCS is also useful out of the pack, on tents, canopies, umbrellas, beach chairs, boats, ATVs and anywhere else you want to cool down.