It can be tough to find the right outdoor workout gear in transitional seasons, when every garment you grab seems to be too hot or not warm enough. The handsome Alpine all-year undershirt from Mammut solves that problem handily. It uses “body mapping” technology that strategically places three different fabric weights to keep you comfortable in a range of conditions, with the warmest layer right around your kidneys. Available in men’s and women’s styles. $65 at www.rei.com.