A steady uphill hike on a cold morning asks a layer to hold warmth while the body heats up and cools down, and the Smartloft Vest answers with insulation that is 50% recycled wool. The wool comes from scraps of merino base layers, and this insulated vest wears as a mid layer that keeps that warmth around the core. What Our Gearhead(R) Experts Are Saying:"On chilly trail walks, I stopped and started constantly, and the vest kept my core warm through every pause. The stretch panels moved with every reach and stride once I picked the pace back up."