Survival · 8 min
Shelter, fire and warmth
Why this matters
Exposure is the New York killer, and the fix is insulation and a windbreak, in that order. Fire matters, but it is a distant third to being dry and off the ground.
By the end of this lesson you will be able to
- Build an emergency shelter with the materials a party actually carries
- Explain the four mechanisms of heat loss and how each is countered
- Build a fire reliably in wet conditions, and know when not to
Four ways heat leaves a person
| Mechanism | What it is | Counter |
|---|---|---|
| Conduction | Contact with something colder, above all the ground | Insulation under the casualty. Pads, packs, spruce boughs, anything |
| Convection | Moving air stripping the warm layer off the skin | A windbreak and a shell layer |
| Radiation | Heat radiating away, mostly from an uncovered head and neck | Hat, hood, reflective blanket |
| Evaporation | Sweat and wet clothing evaporating | Dry clothes, vapour barrier, stop sweating before you stop moving |
Ground conduction is the one people forget. A casualty lying on cold ground in a good sleeping bag will still get cold. Get something under them first, before anything else.
Emergency shelter, in order of what you actually carry
- Tarp or emergency bivvy. Eight ounces, a minute to deploy. Every guide should carry one
- Large bin liners. One as a vapour barrier over the torso with a face hole, one under. Weightless, effective
- Natural shelter. A blowdown root plate, a boulder overhang, dense conifer. Look for something that is already three walls
- Debris shelter. A ridgepole against a stump, ribs, then a thick layer of leaf litter, at least an arm's depth. Slow to build and very effective. Build it small, body-sized, because you are heating it with your body
- Snow shelter. In winter, a tree well or a snow trench roofed with boughs is faster and warmer than anything you can build from timber
Site it out of the wind, off the valley floor where cold air pools, away from standing dead trees, and not in a drainage that will run water if it rains.
Fire
Fire is morale, warmth, drying, water treatment and signal, all at once. It is also a poor substitute for insulation, and building one in a downpour has cost people the daylight they needed for shelter. Shelter first, fire second.
- Site on mineral soil or rock, away from overhanging branches and never on deep duff or peat, which can burn underground for days
- Prepare everything before you strike a light. Tinder, kindling in three grades, and fuel, all within reach. Most failed fires fail because someone went looking for wood with a flame already burning
- Tinder in the wet: birch bark, which burns wet and is everywhere in the Adirondacks; the dead twiggy skirt low on a spruce, which stays dry under the canopy; fatwood from a resinous stump; and the cotton ball with petroleum jelly that lives in your kit
- Split wet wood. The inside of a dead standing branch is dry even in days of rain. Dead and standing beats anything off the ground
- Carry two ignition sources that work when wet: a ferrocerium rod and stormproof matches, plus a lighter that you keep warm in a pocket
Before you light one
Check where you are. Campfires are prohibited outright in the Eastern High Peaks Zone, above 4,000 feet in the Adirondacks and 3,500 in the Catskills outside the winter windows, and within 150 feet of water, roads and trails in the Western High Peaks and Canoe Route zones. Fire danger ratings and burn bans apply too. In a genuine emergency the regulations bend; on a normal night out, they do not.
From the field
Rain, 41°F, dusk, one client shivering hard. You do not look for firewood. You put a pad and two empty packs on the ground, put her on them, a bin liner over, the tarp across a blowdown as a windbreak, hat on, warm sweet drink from the thermos. Ten minutes of that beats an hour of trying to light wet wood.
This lesson is part of the NYS Licensed Guide Exam course. Open it in the course to answer the retrieval checks that go with it, track what you have read, and quiz the whole unit. Lessons, quizzes and the glossary are free.