Scott Macartney’s 2008 crash in Kitzbühel was horrific. When he slammed his head against the ground, his POC Skull Comp helmet ($320; pocski.com) shattered, and he slid, twitching, to a stop. The helmet, however, did exactly what it was designed to do: implode upon impact, saving his life. He’s back on the circuit, with a helmet POC has made even safer by adding multi-impact foam.