This cooling scarf work using only natural evaporation - no chemicals required! Simple soak the scarf in water for several minutes, and the natural evaporation process with provide a lasting cool that you can wrap around your neck.This cooler scarf is an innovative way to cool down while enduring outdoor heat. Made from a new hyperevaporative material (Crystalline polymer) that retains water while remaining dry to the touch. When wet, the towel/scarf becomes considerably cooler than the outside air, thereby providing cooling relief to the user. When it stops cooling (1-4 hours)simply re-wet the towel and wring it out. Within minutes it is cool again.