Self-warming skiwear isn’t new. Skiers have been putting aftermarket heaters in their boots for years, and Columbia and Black Diamond recently debuted impressive (if expensive) battery-heated gloves. But we’ve never tested an electric jacket we liked until now. The best thing we can say about the Columbia Circuit Breaker soft shell, aside from how warm it kept us, is that it doesn’t feel like a heated jacket. It’s a bit heavier than a standard shell—there are two power packs, each the size of an iPod—but because the heat travels along lightweight, flexible carbon-fiber threads sewn into the fabric, it isn’t stiffer than other soft shells. Turning it on is as easy as pushing a chest-mounted button, and the Circuit Breaker really does blaze: on its highest setting, it kept us toasty for more than five hours.