A: I think I know its name: Mountain Hardwear's Monkey Woman Jacket ($115; www.mountainhardwear.com), a piece made with an extremely lofty, warm fleece material called Polartec Thermal Pro. It's a little bulky, but is near perfect either on its own or under a shell—especially under a shell, as it's not windproof. Another good choice would be L.L. Bean's Mountain Guide Fleece Jacket ($99; www.llbean.com), made with another excellent Polartec fabric: Wind Pro 300. That's about the heaviest fleece made, one that's woven very tightly to keep out all but the stiffest breezes.

If you're looking for something warm for those slower moments, though, you might think a little outside the box. It's very hard to beat a light down sweater for its weight/warmth ratio—sweater in this case really meaning jacket, though not essentially weighty enough to be a tried-and-true jacket. Get it? Gear-marketing semantics aside, Patagonia's Down Jacket weighs a mere one pound, stuffs down to the size of a grapefruit, and is far warmer than any fleece jacket out there ($199; www.patagonia.com). Probably too warm to hike in, and not a good rain piece, but if you can bear lugging a little extra gear it would prove to be an extremely useful piece. Heck, you could make up the weight by packing a lighter sleeping bag and using the down jacket as a nighttime warming piece. Marmot's Women's Down Sweater is a tad heavier (one pound two ounces) than the Patagonia piece and about the same insulation rating, and sells for $160 (www.marmot.com). Either would keep you extremely toasty.

For more PCT-worthy apparel and gear, check out Outside's 2004 Buyer's Guide.