The main aim of Evaporative Cooling Neckwear, which includes bandanas, scarves, wraps, towels, and even ties, is to cool the carotid artery. Most of these products work by absorbing and storing water within multi-layered fabric (often containing special polymers or crystals) then slowly releasing that water through evaporation, creating a chilling effect on both skin and artery. Such neckwear can reportedly provide temperatures 15-20 degrees cooler than the ambient temperature, depending on airflow.