Gryphon Gear Taurus VRB -5°F

Our take Thanks to innovative materials and design, the Taurus VRB delivers exceptional warmth in the lightest -5°F bag on the market. And if that’s all you care about, this is your bag. An aluminized Dyneema lining helps reduce all of the ways you can lose heat—conduction, convection, radiation, and evaporation—by reflecting body heat back into the bag and minimizing ventilation (most bags focus on conduction and convection). Drawback: The lining is crinkly and doesn’t stretch, so changing sleeping positions is a wiggly prospect. But, for ultralight winter trips, the water-resistant 900-fill down makes the comfort tradeoffs worthwhile.

The details An optional Dyneema hood (3.5 ounces, $113) slides on your head like a helmet to prevent moisture being exhaled into the bag. The 64-inch shoulder and 54-inch hip girths ensure plenty of room for waiting out winter nights.

$647; 1 lb. 15 oz. (regular); -5°F; unisex regular and long