Big Agnes Sidewinder 0°

The Big Agnes Sidewinder 0 is a mummy sleeping bag rated to 0F, built around Big Agnes's patented Sidewinder side-sleeper design rather than a standard symmetrical mummy cut. The insulation is body-mapped and hybrid - a mix of down and synthetic fill - placed to cushion the hips and shoulders whichever way you roll, which addresses a real complaint side-sleepers have with conventional mummy bags: compressed insulation and pressure points at the hip and shoulder. At 1588 g it's a substantial bag, in line with its 0F rating rather than a lightweight three-season design - expect this on cold-weather or shoulder-season trips where warmth matters more than pack weight. The hybrid fill combines down's warmth-to-weight with synthetic's damp-resistance in the areas most exposed to condensation. It suits hikers who sleep on their side and have found standard mummy bags uncomfortable, more than anyone chasing the lightest possible 0F bag.