Arc'teryx Rho LT Zip Neck Men

This shirt feels soft and warm, with a brushed interior that feels comfortable against your skin. The fit is close-fitting, so you can easily wear a jacket or fleece over it. The flat seams and ample freedom of movement under your arms ensure that nothing chafes or pulls.

It comes into its own best on cold days at an easy pace. Think of a winter trek in the Alps, a cold morning on the Veluwe, or a long, steady endurance run with stops along the way. During a short break or at a windy summit, you notice the difference: you stay warm, whereas a thin shirt lets you cool down immediately. If you do get warm on a climb, simply unzip the high collar and let the heat escape.

If in doubt, look at your pace and the temperature. This is a warm layer for moderate exertion, so you will quickly get too warm during intervals, fast runs, or in mild weather. You will need a jacket over it in wind or rain. If you often run or walk in the cold at a leisurely pace, this is a comfortable, versatile base layer.

In short: a soft, warm base layer for quiet hours in the cold.