I now have both the Under Armour and the Serius balaclavas mentioned in this thread. Serius is much warmer than the Under Armour one. I wore the UA this morning in low 30's F and wind and it was barely adequate. I would not wear it in freezing temperatures. Although, it's cutomizable, you can wear it as hat only or as a gaiter only. But I seem to be more sensitive to cold than most folks so that UA balaclava may work for you in lower temps. But it's basically a shell with no liner. The Serius one has a fleece-like liner and it's much thicker.