When the wind whipping against the tent sounds like winter's claws scraping the world's biggest chalkboard, this cocoon of warmth will fend off any apprehension. Constructed with toasty Thermix insulation and an Omni-Heat thermal reflective lining that traps and recirculates your body heat while providing breathability, the Reactor 15 Mummy is built to keep you comfortable with temps down in the teens.

In addition to Omni-Heat, several thoughtful design details work together to help cancel heat loss: a draft tube along the zipper prevents it from becoming a cold spot, a face gasket cinches down to keep crucial head heat in, and a secondary collar around the neck cinches in for double draft-canceling duty. Featuring a sleek, super soft texture, the shell fabric is outfitted with Omni-Shield advanced repellency to keep out the wet and it's sewn with off-set quilting so there's no kinks in your cold-fighting armor. A trapezoid toe box provides plenty of room for foot comfort. The Reactors are engineered with your choice of a right or left-hand zipper so they can be zipped together to make a couple's bag.