Normal Lycra materials are cooling layers designed to cool the body, this garment has the outward appearance of a Lycra top but has a brushed 'fleece like' inside to provide good thermal qualities. It also remains remarkably dry since the polypropalene material hates water. Wear it under neoprene wetsuits, the Rooster Hot Top, Rooster Thermaflex top, Dry Suit....... in fact the possibilities are endless - this top would be great under your ski suit, down the gym, cycling etc.