Pontetorto, the Italian company that makes fabric for activewear, says that its new Dryfast Adaptive fabric reacts to body temperature. The fabric, intended to go next to the skin, works with the body's own methods of moisture evaporation that it uses to adjust its temperature. Dryfast Adaptive uses a hydrofunctional polymer that was developed by HeiQ, a Swiss company. In the cold, the polymer absorbs and stores moisture in a special film around each fiber, keeping the body warm and dry. When it is hot, moisture is wicked away and the polymer releases the moisture that it stores in the cold; this helps keep the skin cool. Pontetorto says that a 100 percent polyester Dryfast Adaptive fabric has a humidity evaporation rate three times that of an untreated 100 percent polyester fabric when worn at 35 degrees Celsius. The polymer is Bluesign certified. Pontetorto debuted the new fabrics at the Performance Days events earlier this month in Munich and Annecy.