Running the Boston Marathon, hiking the Hundred-Mile Wilderness, kayaking around Long Island – been there, done that, and all demand determination along with a willingness to endure a certain amount of discomfort – but few activities require more sheer willpower than crawling out of a toasty sleeping bag when the outside temperature has plunged to eight below zero.

That was the situation one morning last week when Phil Plouffe, Steve Kurczy and I holed up at Carter Notch Hut in New Hampshire's White Mountains while traipsing around snowy, icy trails for a couple days.

My mummy bag is rated to 30 below, and I had it zipped all the way up so only my snout protruded for breathing.

In all honesty, the temperature inside the unheated bunkhouse was probably only in the teens – though a water bottle Steve left outside his bag had frozen solid – but eventually we would have to make our way to the bone-chilling frigidity beyond the walls. The mountains beckoned.

The best way to extricate oneself from a warm sleeping bag is to do it quickly and decisively, like jumping off a pier into an icy pond. I squirmed out out, threw on my parka, mittens and booties and grabbed two packets of chemical hand-warmers. Phil and Steve also emerged from their downy cocoons, and the three of us hustled down the short, snow-packed hill from the bunkhouse to the main cabin, where caretaker Chad LaFlamme already had hot water boiling for tea and oatmeal, bless his heart.

The Appalachian Mountain Club's Carter Notch Hut, tucked in at 3,288 feet among boulders between Carter Dome to the east and Wildcat Mountain to the west, is one of several shelters throughout the White Mountains open to hikers. In winter, guests may use the propane stove for cooking as well as the hut's kitchen utensils, and sleep on mattresses – a considerably luxury compared to the snow cave some friends and I built and slept in a few years ago while on a winter hike near Mount Madison.

The hut caretaker even lights a wood stove – but not until 4 p.m.

"Otherwise, people would hang around all day," Chad said, watching us prepare our breakfast.

We checked the weather forecast, which Chad had posted after monitoring a radio broadcast from the Mount Washington Observatory.

Hmmm … temps dipping to 35 below on high summits, with 60-70 mph winds. Severe wind-chill risks.

"Kind of brisk," I noted.

However, at this hour the wind had yet to build, and bright sunshine at least conveyed the appearance, however false, of relative balminess. We all wanted to scale at least one 4,000-foot peak – especially Steve, on his first winter mountaineering excursion – and finally agreed on an itinerary: First we would scramble up the 4,422-ft. Wildcat A, only a mile or so from the hut, and then descend. Depending on conditions, we then would venture over to 4,832-ft. Carter Dome, a mile and a half in the other direction.

If we were feeling especially energetic we could then pack all our gear, hike back down from the hut, get in our car and drive to another mountain – but that seemed overly ambitious.

By 9:30, our bellies full of oatmeal, we began our climb up Wildcat Ridge Trail. For such a short scramble I didn't bother carrying even a day pack, and it helped that not much fresh snow had fallen on the well-packed path.

Still, I had forgotten the trail's relentless steepness. Years earlier my son, Tom, and I clambered up Wildcat Ridge from the other direction, Pinkham Notch, and descended with full packs in deep snow into Carter Notch. As I recall we post-holed and tumbled repeatedly, arriving at the hut after dark.

By comparison last week's ascent was a cakewalk, and we enjoyed glorious views of the notch from the summit, including one of the tiny cabin where we had spent the night. Mercifully, the wind remained calm.

There are five separate Wildcat peaks – A, B, C, D and E – but we contented ourselves with tagging the closest, but tallest.

After sliding back down to the notch an hour later, we stopped at the hut, gobbled a quick snack and then headed up the Carter-Moriah Trail, fully as steep and in places more slippery than the Wildcat Ridge Trail.

I silently – well, all right, maybe not so silently – cursed myself for making a bad decision about boots. At the last minute I had decided to leave my heavy, plastic, double-insulated mountaineering boots and crampons in the car, and elected to climb in lighter hiking boots affixed with a worn pair of strap-on traction attachments.

My feet were warm enough, but on precipitous sections I frequently slid off the trail or worse, backwards. Anyway, it was my own dumb fault – I gambled and lost.

It wasn't pretty, but I managed to make my way up to the top of Carter Dome to join Phil and Steve.

"Where's all the wind?" I asked. "Not that I mind."

From the summit we peered east to the Presidential Range, including Mount Washington, Mount Adams and Mount Madison, and from cloud movements it appeared higher gusts were buffeting those taller peaks. I was just as happy to be on Carter Dome, and decided to retrace my steps back down to the hut while Phil and Steve took the long way back that took in a short additional ascent of Mount Hight.

We rendezvoused back at the hut a couple hours later, and by the time they returned I already perched on a bench next to the wood stove, sipping tea.

"Plenty of room by the fire," I said, as if they needed an invitation.

"That was great!" Steve enthused, peeling of his parka. Phil made a beeline for the hot-water kettle and poured a cup of coffee.

Darkness fell like a curtain, along with the outside temperature, but Chad had the stove roaring. He also flipped on lights powered by both a wind generator and solar panels. When the batteries ran out of juice Chad switched on propane-powered lights.

"Nice and cozy," I remarked. "And a lot quieter than last night."

Those of you who read last week's dispatch will recall my comments about a boisterous group of Boy Scouts who also spent the evening at Carter Notch Hut.

They departed immediately after breakfast, so we had the cabin to ourselves.

Chad, 28, who has a degree in adventure education from New Hampshire's Plymouth State University, where he also has taught outdoor-related courses, has spent several winters as caretaker at various Appalachian Mount Club huts.

He was happy for our company, though also enjoys solitude and often goes days without seeing another person. Few friends, Chad said, are willing to hike the 3.8-miles each way to visit – particularly in winter when the temperature often dips below zero, hurricane-force winds can howl and several feet of snow cover the ground.

Like other caretakers he works 10 days straight and then gets four days off.

What does he do in his spare time? What else: "Go skiing, or hiking, or climbing."

Chad kept the wood stove stoked until 9:30, when it was time to turn in.

Though it would be nice to huddle longer near the stove rather than retreat to the unheated bunkhouse, all of us were tired and needed rest for the next day's hike down the Nineteen Mile Brook Trail and 250-mile drive back to southeastern Connecticut.

By morning the long-awaited bitter cold and gusty winds arrived.

"Good timing," I said, as we finished breakfast and strapped on our packs.

An icy blast swirled powdery snow as we crossed the ice-covered Carter Notch Lakes. It looked like a scene from "Dr. Zhivago."

Soon, though, the trail ducked into the protection of evergreens and we enjoyed a placid hike back to the parking lot an hour and a half later.

"A winter hike is like a plane landing," I said, as we tossed gear into the trunk. "Any one you can walk away from is a good one."