You might get cold in the Sierras unless you are geared up in
the Women’s Virtuoso Down Jacket from Outdoor Research. The 650-fill
down holds body heat in so you stay nice and toasty, and you can seal
out cold air by cinching the dual hem drawcord and tightening the
hook-and-loop cuff tabs. The entire jacket compresses into one of the
hand pockets so you have a compact, packable jacket that doubles as a
down-filled pillow when sleepy time comes around.