Patagonia's Nano Puff Bivy Pullover is light, windproof, warm and has the pared-down features that help shift the odds in your favour. The water-repellent, compressible 60g PrimaLoft Gold Insulation Eco has a superb warmth-to-weight ratio and maintains 98% of its warmth, even when wet. The interlocking fibres of the lightweight, 100% recycled polyester shell and liner fabrics block wind, shed moisture and enhance the DWR performance. When the going gets cold, the kangaroo-style handwarmer pocket and a close-fitting, under-the-helmet hood with elastic binding bumps up the comfort level. The zippered drop-in torso pocket doubles as a stuffsack with a reinforced carabiner clip-in loop. With a deep venting centre-front zipper, elastic-bound cuffs and a drawcord-adjustable hem.