No gasping. If you choose to hike in pants that have been implicated in hundreds of cases of near-fatal hypothermia, it's no skin off my nose. But I will say this: I essentially live in blue denim jeans around the home, office, wood shop, and yard, but find them utterly impractical in every way for hiking and camping. They're not warm when it's cold, too warm when it's warm, and, of course, incapable of shedding water.
Beyond that, there are all sorts of practical pants for outdoor use. For cool and damp weather, look no further than L.L. Bean's Schoeller Dryskin Guide Pants ($125; www.llbean.com). Expensive, yes, but also durable and superb across a wide temperature range.
They're almost dark khaki, so does that make them "slacks"? Your call. Mountain Equipment Co-op, meanwhile, has what it calls the Karma Stretch Pants. These use a mix of materialsCordura, nylon, and Dryskinto make a tough, comfortable, close-fitting pant that's also not too tight. Best of all, they're $89 Canadian, or about $60 U.S., and can be ordered online (www.mec.ca). They come in tan, black, or dark brown, the last two being almost jean-like colors, I suppose. Finally, take a look at Gramicci's QwikDry Pants ($48; www.gramicci.com), a simple, cleanly designed pair of pants made of sanded nylon that are designed for active use.
Trust me, ANY of the above will work much better than jeans, while not offending anyone's outdoor sensibilities.