These new midweight RedHEAT PRO kids' base layer pants are made of innovative temperature-regulating fabric. Thanks to the Red Heat-infused technology that provides warmth, our kids’ base layer is perfect for any winter sport your little ones want to do this season. These thermal long johns also feature ventilation zones on the back and sides, ideal for moisture management. With the addition of a gusset for better mobility and 4-way stretch fabric, this is the ideal kids’ thermal base layer for playing in the snow all day long.