Polyisoprene is often considered the “best of both worlds” for those with latex sensitivities. Here is how it compares: Feel & Stretch: Unlike polyurethane, which is plastic-like and less stretchy, polyisoprene is a synthetic rubber. It offers the soft, elastic feel of latex without the proteins that cause allergies. Heat Transfer: Polyurethane is the thinnest and conducts body heat best, …