Full of hot air?Put it to good use this winter with the new Airvantage technology from Gore, found in Burton's Radar Type Z jacket (800/881-3138;; $550) and Hugo Boss's Airvantage (800/484-6267;; $995). When you feel cold, breathe into the hidden tube—it fills a maze of air chambers inside the coat to warm you up. —Jaime L. Gross