Light conditioning. Why use ThermaSilk Volumizing Shampoo + Conditioner? Provides light conditioning while shampooing without weighing down hair. The only Volumizing 2-in-1 with our heat-activated moisturizers to improve your hair's condition while heat styling. Works with the heat of your blow dryer to boost body and volume of even the finest hair. What does Heat-Activated Mean? The ThermaSilk heat-activated moisturizers help lock in your hair's moisture that can be lost during heat styling - transforming a dull, lifeless texture into softer, silkier hair.