Think breathable space blanket. This proprietary insulating liner system from Columbia keeps you up to 20% warmer than traditional methods. The inner liner of these garments have 35% of their surface area covered in tiny, reflective dots that bounce back body heat generated by the wearer to keep you extra warm. The remaining material is an ultra-breathable, moisture-wicking material that helps disperse moisture and any excess heat. Look for this lining in Columbia coats, pants, and even gloves.