Is it a baselayer shirt or lightweight jacket? Both, actually, and often on the same trip. During 10 days of cool, gusty, and rainy Alaskan weather, our tester pulled the Bat Hang over a T-shirt as his primary insulation. On alpine starts in Colorado, he wore it as a baselayer from trailhead to summit.
"I love the comfort range," he raves. "With the hood down, it's like a microfleece shirt. With the hood on, it's almost as warm as a thin puffy jacket. And the deep chest zipper and breathable, quick-dry polyester kept me from overheating." The hood is one of the best we've seen: It zips up high for neck and face protection, and the zip is offset so it doesn't track across your chin and mouth. $99; 12.3 oz. (men's XL); men's S-XXL, women's S-XL; firstascent.com