Adidas have recently expanded their 'Clima' products to include the Climaheat fabric technology. Climaheat is a trademarked fabric that's purpose is to provide insulation / warmth by trapping body heat. The other advantage is that the fabric will dry faster than traditional fabrics when wet. The Climaheat fabric uses hollow-core fibers to enable superior insulation; Adidas have not implicitly explained how the hollow-core fibers traps heat, but that is it's purpose.
One drawback to Climaheat is that it is a delicate fabric and Adidas recommend that people only wash Climaheat apparel on a 'delicate' machine wash: no more than 30°. Adidas also state that Climaheat apparel should not be tumble dried and should not be ironed. At present, there is only a handful of Climaheat products; they mostly appear to be designed for rambling, walking, jogging, outside exercise and general outdoor pursuits. The apparel is fairly bland in design, and cannot be mistaken for sportswear designed as fashionwear. At present, the following Adidas apparel has Climaheat fabric: hoodie, sweatshirt, jacket, gloves, tights, and a 'beanie' heat.