I am always cold.....always. I need a light, packable and VERY warm jacket for backpacking. I've been cruising the web looking at all of the different brands and fabrics and fills and reading the reviews. All of them claim to be very warm but none of them give an actual temp rating, like "good down to 10 degrees" etc the way sleeping bags are rated. So far I'm favoring the Patagonia micro-puff (which seems to be nearly impossible to find in a small woman's size - a small man's is going to be too big) because I saw so many people wearing it last March on the AT. However I was very unhappy with Patagonia's capilene base layers - pricey and I was never warm in them, so I am suspect of their warmth claims for the jacket. I know that asking for advice means I'm going to get 20 answers with 20 different brands recommended but I'm hoping for some sort of "most popular" answer. I'm 52 and menopause is nowhere in sight so I can't hope for hot flashes to stay warm! I'm always the one woman in a room who is not too warm, not opening windows and doors, not using a fan at my desk...........