As temperatures in the Hudson Valley and Catskill Mountains plummet below freezing, some of us curse the frigid air, pop a bowlful of buttery popcorn, and curl up on the couch for the opening of a guilt-free early evening movie session. Others unpack their crampons, fluff their fleece jackets, and waterproof their insulated hiking boots. They revel in a different opportunity, one brought by ice and snow.

Carol and David White proudly claim the latter camp. As members of the Catskill 3500 Club, this winter they'll spend as much time as possible on the ice-covered paths of the tallest of the Catskill Mountains. And for the summits that have trailless ascents, they'll bushwhack across the snow.

The discovery of mountain hiking clubs changed Carol White's life. In a recent letter to the editor, published in the New York Times, White describes herself as someone who was the type who avoided gym in school, smoked for 33 years, and was in her late 40s when she discovered mountain-hiking clubs. "Hiking up mountains in the Catskills, the Adirondacks, and New England on a regular basis has made me stronger than I was 20 years ago as a smoker," White writes. (As a team, the Whites have gone on to publish many hiking and trail books, including the essential Catskill Day Hikes for All Seasons.) One of the hiking clubs Carol discovered is the Catskill 3500 Club. Membership is earned by climbing all of the 35 peaks over 3,500 feet in the Catskill Range, plus the Slide, Balsam, Panther, and Blackhead Mountains a second time in winter.

Membership in the elite Winter 3500 Club is granted after climbing each of the 35 peaks in winter. Bagging winter peaks comes with winter dangers the likes of which would make the couch potato shiver under his or her comforter: frostbite, avalanches, unforeseen snowstorms, damp chill. But many disasters can be avoided. A common mistake made by novices is not bringing enough warm clothes, warns club member John Graham. Experienced hikers always stuff an extra down or synthetic parka into a larger pack for use only at rest stops or in case of an emergency. "Many beginners do not carry this coat. This is an accident waiting to happen," says Graham. And of course, the rewards are greater than any movie can provide-the experience of hiking across untrampeled, virgin snowfall below tinkling, crystal-covered branches, and the feeling of being the only person to set foot in such conditions on a normally well-traversed trail. "The cold in itself, once you get to know the winter, can be valuable because you won't get wet. What I don't go out in are above-freezing temperatures," says Graham.

The 3500 Club offers weekly member-led hikes, which are listed in the quarterly Catskill Canister newsletter (excluding the weeks during deer-hunting season). These group events are an opportunity for less experienced hikers to learn from people who have logged more upward miles. "You have the option of going on hikes with someone who has been there before. Alternatively, if you're an experienced hiker, you can purchase the Catskill map set, and organize hikes with your friends," says board member Wanda Davenport.

As well as being a support group of sorts, the club is actively involved in environmental issues. A conservation committee works to preserve wilderness in the Catskill Forest Preserve, and for more than 30 years the club has maintained a section of the Long Path in the Catskills.

To find out more, visit www.catskill-3500-club.org. To join the discussion group, investigate trip reports, or ask questions on current conditions, e-mail 3500clubsubscribe@yahoogroups.com. Non members may request the 3500 Club's quarterly hike schedule and Catskill Canister newsletter by e-mailing Jmw755@aol.com or by sending $10 to Judith Weiner, 755 Anderson Avenue Apt. 4J, Cliffside Park, NJ, 07010.