Helly Hansen Bodywear made with polypropylene, absorbs virtually no moisture and is extremely elastic thereby providing direct venting through the pores that open when the garment is worn. The fabric allows excess heat and moisture to escape so that the Bodywear therefore stays dry next to the skin.
Helly Hansen's heavyweight Poly-Pro™ will keep you warm and dry in the most miserable weather. Poly-Pro™ works on the principle that wet skin becomes cold skin, leading to chilling and hypothermia. Poly-Pro™ won't trap moisture next to the skin. Body heat pushes sweat through the fabric, away from your skin to the next layer of clothing. Poly-Pro™ is machine washable, hang to dry.
The polypropylene fiber was invented by Italian researchers for which they received the Nobel Prize in 1963. Polypropylene is a hydrophobic or water repelling fiber which does not absorb moisture (0.01%). As no moisture is absorbed or permanently adhered to the fiber or yarn the fabric remains dry next to the skin.