The Ibex Randonee Pullover brings wool back to the woods.

WHILE FEW would argue that the humble sheep offers any sort of benchmark for animal IQ, it's hard to trump the brilliance of ovine design when it comes to temperature control: Wool keeps you warm when it's cool out, cool when it's warm out, and doesn't even begin to feel wet until it has absorbed 40 percent of its weight in water. So it's nice to see innovative clothing manufacturers going back to the farm. Using modern milling techniques that eliminate scratchiness and enhance durability, companies like SmartWool, Devold, Icebreaker, Woolrich, and Ibex are rekindling a love affair between outdoor enthusiasts and wool that ignited sometime around, well, 7000 b.c. and blazed brightly until the debut of down in the early fifties.

The Ibex Randonee Pullover ($235; 800-773-9647; www.ibexwear.com) features a soft weave of merino wool on the inside with a synthetic flexible fabric made by Schoeller called "Skifans" on the outer surface. The result: a light, breathable, wind-resistant shell that solves a problem Ibex president John Fernsell understands all too well. "When I run or ski, I overheat and sweat like a 400-pound fat guy," he sighs. "But wool's climate control is distinctive. Basically, you can wear it at 45 degrees or 20 degrees without changing a thing." Of course, sheep knew that all along. —Kevin Fedarko