Polyacrylate fiber that absorbs moisture and uses it to generate heat through an exothermic reaction. Unlike insulation systems, which just retain body heat, this fiber actually generates heat. The combination of properties of the polyacrylate fiber creates a “micro-climate” against the skin. The high level of moisture absorption keeps the skin dry, but the fiber also discharges moisture quickly, keeping the garment from becoming sodden. When exposed to moisture, the fiber generates heat, showing an increase of around 3 ˚C (5.4 ˚F). Unlike most fibers, the presence of moisture does not lead to evaporative cooling, but rather high-speed adsorption converts the moisture or vapor into heat. The fiber can be used in blended yarn constructions and directly in knit and woven constructions, or plied with other yarns for bulkier constructions. Additionally, the fiber decomposes acidic and alkali odors. The yarn is not dyeable and has a light peach color. After blending and finishing, the final fabric will always have a mélange effect. Applications include outdoor apparel, jackets, and bedding.