Climasense™ is a multi-level product line consisting of uniquely engineered garments that are either heat generating (HG) and/or thermal regulating (TR). Each garment is designed to provide comfort and optimal moisture and temperature management. Based on weight and specific HG or TR characteristics, Terramar assigns a warmth factor to every product allowing you to quickly select the right baselayer for any activity. TR provides a warm effect when you are cold and provides a cool effect when you are warm. HG technology features hollow core yarn which captures the body's heat and prevents warmth from escaping. The 4 levels are: a) 1.0 Trailhead TR b) 2.0 Thermolator TR c) 3.0 Ecolator TR and d) 4.0 Glacier Fleece HG/TR.