Any thoughts on worthy base layers?

A: I wouldn't give up on silkweights. Patagonia's Silkweight Capilene ($34 for the Silkweight Crew; www.patagonia.com) is one of the best-wicking, fastest-drying synthetics out there. It's my preferred choice if sweat will be an issue. And I've worn it under packs without any problem at all. The seams are flat-stitched, so rub very little. Besides, I'm surprised to hear a tough adventurer like you mincing around about how some stitching might "irritate" your skin. Très delicat!

Another fabric that might work very well for you is Polartec's Power Dry. It's a bi-component fabric, meaning it has two layers—a fuzzy inner layer that vacuums up moisture, and a "harder," more finished outer layer that disperses moisture and lets it evaporate. REI uses it in a very practical zip T-shirt called the Power Dry Zip T-Neck ($36; www.rei.com). This winter I've been wearing this material while skiing and biking, and think it's terrific. A little warmer than the Silkweight, but by no means too warm for cold-weather skiing.

You might also give wool a try, especially merino wool, which is fantastic at absorbing moisture due to the little pockets that exist inside the wool fiber. You may also find you sweat less because wool is generally more breathable than synthetics. The downside is that it's apt to stay damp for a while. But there's no real harm in that, as wool retains much of its insulating quality even when wet. SmartWool, one of the companies that has really brought wool "back," makes a shirt called the Aero Crew ($54; www.smartwool.com) that is supposed to wick faster than synthetics. Also check out the Icebreaker Original Zip T ($110; www.icebreakernz.com), a terrific wool shirt.