It may seem extravagant - they aren't cheap - to wear merino wool boxer shorts or panties, but if you need breathable, comfortable underwear that you can comfortably wear for several days, there's nothing comparable. Try a pair for your next expedition: you'll save space in your pack, won't have to wash them nearly as often, and in the long term, will have to spend less money on underwear because they're so durable. We can't recommend merino wool underwear enough.