hen you get your first glimpse of Byron Kerns, in a farmer's field at the foot of the Blue Ridge Mountains, that 17-inch machete could give you the wrong impression.

This impression would be wrong because while Kerns is squarely built and brawny-armed and wears that machete in a way that suggests it isn't just for effect, he will greet you with a reassuringly firm handshake and a voice as soothing as a bedtime story. And you will immediately begin to feel much more confident about your decision to sign up for Kerns's Mountain Shepherd weekend wilderness survival school.

I arrived for my class, about an hour south of Charlottesville, early on a spectacularly beautiful Saturday morning with the sky a bottomless blue. My five classmates were James, a quiet computer specialist from Northern Virginia; Sutzi, a backpacking enthusiast and returning student looking to brush up on a few skills; Carl, an affable outdoorsman and trained search and rescue team member; and Tim and Anne, young twenty-somethings who arrived together.

Why were we here? For me, it was the realization that a childhood of hiking and tent camping had left me one of those foolishly smug people whose confidence in the outdoors dangerously outweighed my actual preparedness; I was shaping up to be a two-column-inch statistic under the heading "Hiker Found, Frozen" when my dumb luck ran out. Others in the class had reasons ranging from skills improvement to learning how to forage on wild plants (to which Kerns's ultimate response would be -- "don't").

We hadn't walked more than a few hundred yards toward our hilltop camp when Kerns stopped us for our first lesson. Gear.

"If you've got it, keep it dry."

Well, you couldn't argue with that. I don't know what I had been expecting, exactly. Some abstract philosophical dictum about learning to think like a tree, perhaps. I had imagined, for some reason, that minimalism was the height of survival aesthetic, that we would learn to melt into the forest and live large off the land with nothing but a penknife and a pair of shoelaces, like a cross between Natty Bumpo and MacGyver. But Kerns quickly scotched that notion, telling us, "Survival is being aware of the forces against you and thinking ahead and being prepared."

Or, to put it another way, "If you want a fire, bring a flame-thrower."

I assumed we were meant to take this suggestion metaphorically, but it was the same basic idea he would espouse throughout the weekend: "Hope for the best, but prepare for the worst."

When it comes to the outdoors, Kerns said, "Too many people come dressed to arrive instead of dressed to survive. They think 'This can't happen to me.' That's selfish! It can happen to me, it can happen to all of us."

Kerns believes that equipping yourself with the knowledge and the tools to survive is something you do because someday you could use those skills to help someone else.

"You can look at it selfishly, that 'This training's for me,' " he said. "But what I want to impart to you is knowledge you can share with others. You might be in the wilderness with someone else, and you can have the capability to help that person. You help others, you help yourself. That's my philosophy."

We would find it was a highly infectious philosophy. It wasn't long before all of us were practically throwing ourselves at each other in our eagerness to assist, to share our food and our extra thises and thats, to pick up a dropped hat or pen.

We'd come expecting "Survivor" and ended up in "Mister Rogers' Neighborhood."

Kerns, a former survival instructor for the Air Force, has been spreading his philosophy for more than 25 years, teaching everyone from astronauts to Navy SEALS to, once, "a group of 13 preachers." He launched the Mountain Shepherd school in Amherst, Va., about four years ago and offers several different classes, the most challenging of which is the grueling, four-day Humble Thunder in which, Kerns noted with ominous cheeriness, he introduces students to a variety of survival "stressors."

In Kerns's school, our dormitories were tents and our classrooms a wooded hill, a stream and an open meadow. Our lecture hall was the "fire circle," a bare patch of earth beneath the canopy of an orange, white and tan 1964 military parachute. A semicircle of camping chairs faced a lectern of logs lashed together and to the canopy's central support, a tall sapling, by parachute cord. (True parachute cord -- seven strands of thread within a woven casing -- is the duct tape of the great outdoors. Endlessly versatile, as everything from a fishing line to a lasso for pulling down dead branches for firewood, it is very lightweight yet has a tensile strength of 550 pounds. "If you can break it, you don't need to be rescued," Kerns noted dryly.)

The first order of business was pitching our tents, which Kerns provided, in the wooded areas surrounding the fire circle. Kerns offered pointers (camp under a tree for added shelter, but first "look up and see what could kill you") and we each sought out our own secluded patch of forest. When we had gathered again in the fire circle, instruction began in earnest. Each lesson offered just enough detail that we came away feeling confident we had learned something valuable that we could put to use in our own lives.

"The brain is your best survival tool," Kerns stressed from the beginning. It will help you avoid getting into a survival situation, and it will help you get yourself out of one. "Learn to remain strong," Kerns advised, to protect yourself from debilitating conditions such as hypothermia and dehydration that can sap your brain's ability to figure your way back to safety.

First on Kerns's list of survival skills, then, is Positive Mental Attitude. If you find yourself in a survival situation, "Stop, Think, Observe, Plan." And prioritize. Then, in order of importance, come first aid, shelter, fire, water, signaling and rescue, and food. (Yes, folks, forget your whining gut; food comes last).

In a survival scenario, even a blister can make a bad situation worse, which is why first aid ranks second on the list. "Say you were out getting firewood, and you got a bad cut from your knife," Kerns asked, turning to Anne and James. "What should you do?"

Playing out the drama, James stepped outside the sheltering canopy then staggered back in looking stricken and holding his arm stiffly in front of him like an extra from "Night of the Living Dead."

"Oh gee, sit on down here and I'll take a look," said Anne brightly, unperturbed, depositing James on a handy stool before he had a chance to pass out from shock.

Holding James's arm over his head and pressing her bandanna against the imaginary wound to stanch the blood flow, she pronounced confidently, "That's not too bad. You'll be fine, you'll be fine."

Thunderous applause, then Kerns stepped up to say that Anne had done all the right things -- kept James calm, put pressure on the wound and elevated it, and most important, demonstrated Positive Mental Attitude.

Shelter, we learned next, "can mean the difference between living and dying," and we practiced rigging an impromptu tent in less than five minutes with a plastic drop cloth, parachute cord and a simple timber-hitch knot easily done -- and undone -- by cold, stiff fingers.

"Don't make it complicated," Kerns said.

In a real pinch, a large plastic garbage bag will do, with a slit for your face where the side seam meets the bottom seam (thus keeping your head covered). Tim, a tallish fellow, demonstrated, somehow folding his entire frame into a bright orange bag, where he crouched, looking like a fluorescent gnome.

As the afternoon wore on, we talked about water and we talked about "wayfinding" -- about the importance of knowing how to use a map and compass. "If you have those, you can help yourself as well as others. You should know where you are at all times," Kerns said.

Our final lesson of the day was firecraft. We would each have to build our own small fire for cooking dinner and for breakfast in the morning.

We gathered our fuel, following Kerns's directive to look for dry wood that snapped crisply when broken. When we had reconvened in the fire circle, Kerns produced a series of gallon-size, resealable plastic storage bags from a small backpack. One held folded newspaper. Another held cotton balls, a small jar of petroleum jelly, a chunk of cedar, a hunting knife and a flint. Yet another bag was stuffed with dry grasses and other flammable materials.

Forget rubbing sticks together; with cotton balls and petroleum jelly, even my cat could start a fire. Kerns demonstrated, extruding the cotton and smearing it with jelly. One flick of flint against knife and they went up like Mrs. O'Leary's cow shed.

"Ooooh," we all murmured, like the crowd at a fireworks display. Then we each set to work getting in touch with our own inner pyromaniac.

For the record, I have the attention span of a housefly. While everyone else carefully laid exquisite little tepees of delicate tinder atop their cotton balls, what I threw together looked -- well, it looked a lot like a pile of sticks. "Good enough," I said to myself, snatching up knife and flint.

A single spark, and the cotton balls burst into flame. The dry tinder began to crackle and curl. "That's the coolest thing I've ever done!" I squealed hyperbolically. At which point the whole thing promptly collapsed like a dot-com IPO. My fire was toast.

Personal wilderness survival rule No. 1: Patience is a virtue.

Personal wilderness survival rule No. 2: Bring extra cotton balls.

With Sutzi's sympathetic aid, I finally got a fire going, and as dusk settled into the forest around us our dinners were soon bubbling invitingly. We shared, of course. Then at last, sated and warm, we extinguished the one remaining fire, bade each other good night and were swallowed by the darkness, each headed to our own frail outpost of shelter in the night.

Shivering, I hurried into extra polypropylene underwear, scooted down into my sleeping bag and doused my flashlight. Then all was still and quiet. Really quiet. For a few minutes it was a nice, relaxing quiet. Then it started to feel like one of those big, empty, unnerving quiets where you lie there, ears straining against the ominous silence. Waiting in dread for a noise.

From personal camping experience, I happen to know that a 500-pound black bear inexplicably manages to slip through the forest with the silent stealth of an assassin. There's nothing quite like waking without warning to the sound of something largish snuffling inquisitively at your tent zipper. While it is true that black bears almost never attack humans, how comforting is that fact when only a few millimeters of nylon stand between you and a very large carnivore?

During the bright, carefree hours when the sun shone warm upon the earth, Kerns had assured us that he had never seen a bear on this property. Yet.

In the morning, Sutzi said to me, "Why do you think I pitched my tent next to the guy with the machete?"

And the first lesson Kerns had for us after breakfast, by an amazing coincidence, was about fear. Kerns admitted, machete notwithstanding, that he himself often was unsettled by mysterious noises in the night.

"It's okay to have fear," Kerns said. "Acknowledge and identify and understand your fears -- don't hold them against yourself."

Speaking of fear, if you have a dread of things with too many legs, or too few, take comfort in the thought that the average person can go three weeks without food and, properly prepared, according to Kerns, "You should never be in a survival situation more than 72 hours." Because when we talked about food, the word was: bugs. Beetles, crickets, grubs, earthworms -- ounce for ounce they're your safest and most nutritious bet.

It's best to roast them.

"White grubs are rough to eat raw," Kerns said.

Having digested this memorable lesson in crisis cuisine, all of us seemed keenly focused when Kerns moved on to getting yourself rescued, quick.

The crowd-pleaser of signaling devices -- the signal fire -- is the grand finale of Kerns's weekend survival class. We gathered dry wood to generate fire and green pine boughs for smoke, carried them down to the stream by the open field and then slowly assembled them on a seven-foot-tall, three-sided log frame erected midstream. It was a long job, and when finished, bristling under its blanket of pine boughs, the whole thing had the faintly risible look of a fuzzy green alien on three legs.

Our labors complete, we lazed about in the sunshine, practicing signal mirror technique while pricking our ears for the sound of a distant airplane engine. Our goal was to catch the attention of a passing small plane, then send it off with an "all-clear" signal. Carl was designated torch man. I was backup Bic.

There was a mounting sense of anticipation as we scanned the blue, blue skies. Then we heard it, the unmistakable buzz.

"Go, go, go!" we cheered Carl on as he raced down to the creek bed, splashing through the shallow water. He disappeared behind the greenery. The plane came into sight over the edge of a hilltop. Anne waggled the signal mirror. And then our signal fire erupted into a fury of flames and a great cloud of white smoke that coursed skyward in a billowing column.

The five of us newcomers stopped and stood there, our mouths agape.

"Whoa!" was about the gist of our thoughtful commentary.

But it was too late! The plane had veered off. The smoke drifted up into an empty sky. We were crushed. Even Kerns seemed dismayed. But we had our cars only a half-mile away and hot showers waiting for us at home. Imagine what a test of your Positive Mental Attitude it would be to see all your work go up in smoke when you were truly counting on it.

We toppled the smoking remnants of the fire into the stream, carefully extinguishing every ember, and then at last it was time to go. Strangers only yesterday, unlikely ever to see each other again after today, nevertheless when we arrived back at our cars we lingered, talking, laughing, reluctant to let go.

It wasn't about fire or water or food. It wasn't about parachute cord or plastic bags or signaling skills. But we had learned the lesson Byron Kerns set out to teach us.

THE MOUNTAIN SHEPHERD SCHOOL -- 220 Regal Oaks Way, Amherst, Va. Offers courses throughout the year. The Weekend Survival Course is co-ed and for ages 9 and older. There is a maximum of 10 participants per course. Tuition is $95 per student. Tents provided, if desired. Parent or guardian required to join participants 9-17. For more information, contact Byron Kerns at 804/929-5309 or via e-mail at mtnshep@aol.com. Web site: www.mountainshepherd.com.