The joke was on me, though, as I found out on a crisp fall ride through New York state. Though the elevations we ascended were minimal, the AirVantage nevertheless allowed me to control the amount of insulation I required from stop to stop. And when we rode the ferry over to Long Island, I inflated the multiple air chambers and went out on the deck to see if I could feel the difference. By adding or letting out air, I could vary the amount of body heat being lost, thus adjusting the temperature of the vest. The thick air cushion worked against cold temperatures because air is a poor conductor of heat. Also, because the vest is designed by W.L. Gore & Associates Inc., it incorporates Gore WindStopper fabric into the outer layer, which served as an added waterproof, windproof and breathable barrier against the icy blasts of the Long Island Sound.