After purchasing several icebreaker shirts and found most of them exceptional I decided to give the backcountry-tee merino wool version with thumb loops a try. My daily involves water monitoring activities 12 months in Michigan's UP. While traversing a steep, leaf covered rocky slope, my right foot became entangled in a hidden log, stopping my forward motion, and sending me crashing to the rocks, cracking my left petella; however the backcountry merino tee with its extended sleeves protected my palms as they broke the rest my fall with the 50# pack adding to the force of the impact on the rocks. I considered sending it back for a new one as it stained quite badly and ripped from impact, but it still works. Weather was rain and sleet; with Northface coat and the merino shirt next to my skin kept me warm thoughout the ordeal. Slim fits would be better, otherwise a pure bargin......