Evaporative Cooling Clothing works under the same principle your body uses to cool itself. Your body sweats, the moisture on your body evaporates and this cools your body. The lower the humidity the greater the ability for the moisture to evaporate and provide the cooling effect.
The polymer crystals turn into gel and hold moisture. The crystals will hold the water in a way that will not make the hat feel wet to the touch after the hat is hydrated properly and the fabric slightly dried