This lightweight layer will keep you warm but has the possibily of being a bit rough against your face.

This Merino is warm, even though it is very thin material, dries quickly, but is a bit scratchy. The neckie is a long tube that goes over the head and around the neck and it doesn't have much weight or bulk. It washes well and is useful on cold mornings when you need a layer for your face that you know you are going to want to shove in a pocket later (it folds up a lot smaller than a fleece neckie). The only drawback is the itchiness because of the wool; it becomes rougher as it is dampened by snow, breath or sweat. It is tolerable and doesn't prevent me from wearing it (as it is such an easy, warm layer to keep in a pocket), but definitely a downside in its functionality.