This neck cooling scarf works by absorbing water and then by evaporation. It works like a fridge. The crystals in the scarf soak up water ( after immersion) and when worn the water evaporates thus cooling you down. This is the same principle as sweating. When water or liquid evaporates it cools down so you will fee cooler.This is a best selling product.
NATO Number NSN-8415-99-498-8961