During the activity of snowmobiling you generate moisture (sweat). The harder you ride, the more moisture you generate. Cotton products trap this moisture, which in turn, transmits cold directly to your body.
For more extreme temperatures, the Arctiva Insulator series provides the additional warmth required. The Insulator gear is made of a blend of micro polyester fleece/Spandex and combined with the Regulator layer, provides extra warmth in extremely cold environments.