The BCB Neck Cooling Scarf is a simple but highly effective body cooling product which works by evaporation.Immersion in clean water for approximately 15-25 mins allows polycrystals in the scarf to absorb and retain a large volume of water. When worn, the retained water evaporates and draws away body heat creating a cooling effect. Cooling can also be effectively increased by placing the scarf in a fridge. Great when backpacking or walking in hot or tropical climates. Staff in the Ready To Leave warehouse have been wearing this product, so we are in a position to say that these are brilliant for cooling down. Include one of these in your backpacking equipment packing list.