» What it is: A 27-inch-long, 10-inch-wide seamless tube of merino wool that can be used to heat and cool the head and neck. Available in Europe since 1992, Buff came to the U.S. in 2003 made of synthetic material.

» How it works: Despite a ridiculously simple design, it works in many shapes and incarnations. The Spanish manufacturers say it can be used 12 ways: as a cap, a bandanna, a scarf, a balaclava, a hair scrunchie and a headband, among others.

» The good: It’s soft, breathable, packs light and can indeed be used in many contexts. In the first few days I had it, I used it as a cap, scarf and balaclava (covering my ears and face, beneath a baseball cap) during a chilly fall football game. And merino wool — comfortable, odor-resistant, sweat wicking — is quickly becoming one of my favorite fabrics. This would be a must for trips to cold or warm locations — it is thin and breathable enough to deal with sweat and sun as well as cold.

» The bad: I didn’t have one before now.

» Cost: $27

» Available: buff.eu, REI and local retailers

–Josh Noel / McClatchy-Tribune