Walking Home

reveries of an amateur long-distance hiker

Vital Heat

October 16th, 2015

Vital Heat


In Coming into the Country, John McPhee offers a series of portraits of Alaskan backwoods men and women. One particularly striking character is Dick Cook, an able trapper who among other quirky traits disdains wool, wearing instead cotton, the one fabric every outdoor adviser warns against. We’ve all heard the phrase “cotton kills” because, once wet, it offers no warmth. Cook claims, “You have to worry more up here about overdressing than underdressing. The problem is getting overheated.” It is perhaps easy to dismiss his comment as Alaskan individualist bravado, but he also is calling attention to the delicate practice of thermoregulation in the big outdoors.

In the “Economy” chapter of Walden, Thoreau uses the phrase “vital heat” to describe the basics necessary to sustain life (or perhaps even to define life). He goes on to critique fine clothing and the fashion industry and, later, elaborate architecture. For him, clothes and houses exist to maintain heat/life, not to designate status. This is all part of his familiar plea to simplify and his broader critique of overly complex social relations. But, if you think a bit about being in the big outdoors over time–that is, to be like Dick Cook working all day outside and perhaps sleeping in a thin shelter at night–this notion of vital heat might be less an opportunity to tweak the noses of Thoreau’s fellow townspeople than it is his acknowledgment of a real and constant imperative which only creeps into conscious awareness outside sealed, climate-controlled spaces.

My experience the other day (detailed in my Te Araroa journal) attempting the Tongiriro Crossing is illustrative:

All advice is not to attempt [the crossing] in bad weather, and my morning started out cold (down at low elevation) and wet, though there were glimpses of sun, and the cloud cover did not look significantly different from a typical New Zealand morning, so off I set. My plan was to get up to the Ketatahi Hut which was about 18 km from the campground and a little over six from the car park. I figured to get there mid-morning and would then have a sense of how the weather would play out. If it stayed bad, I’d sleep in hut and wait for morning. The hike went well, long road walk followed by well-designed and maintained paths. As I emerged from the bush and started hiking the alpine tundra the temperature started to drop as I expected, and the wind picked up. I could smell the sulfur from the hot springs nearby. Still, I was well dressed in wind/rain gear, ready for what I thought would come. The trail has been rerouted a bit since I last hiked this track (I’ve already done this stretch twice before, but in summer weather), so I was not sure how close the hut was. The rain intensified and the wind soon got to gale force. It at times actually pushed me off the trail. The last kilometer or two were otherworldly– horizontal rain, freight train wind, and no clear end in sight. Then it appeared (not a moment too soon). The first thing I saw when I got to the door was the hut’s redesignation as a temporary shelter, not an overnight site any longer (because of a recent eruption– after all, this is a volcano hike). I went inside, stripped off wet clothes, and with shivering hands made an early lunch. As I did not get appreciably warmer–the wind by now was bashing the sides of the cabin– I spread out my sleeping bag on the table and crawled in which soon got my body temperature to a better range.

Here the great outdoors is threatening and heat is indeed vital. Its maintenance is something requiring anticipation, preparation, and self-awareness. I used all the elements Thoreau details for proper balance–food, clothing, shelter–but my getting to that level of understanding about vital heat was the result of a specific crisis. It is the day to day that tends to slip beneath notice but is perhaps what Thoreau is actually signaling through his discussion in Walden.

Dick Cook rejects wool clothing because of the expense, but also because he lives near Eagle, Alaska which happens to be in the driest part of the state. Places with high moisture and sharp temperature shifts require more deliberation. Even though I have a slight wool allergy (it itches a lot), that is what I wear on the trail. The main difference between merino wool and polypropylene (the other backpacker fabric of choice) is that wool is warmer, dries quicker, and–a perhaps aesthetic but still important difference–wool does not smell after a few days’ wearing (nothing reeks worse than polypropylene after a couple of sweaty days). But maintaining vital heat is not so much about the material as it is a set of practices in relation to your own body’s heat response. A typical hiking day for me: early mornings are usually cool, so I often start with long pants (I hike with zip-offs, so at a break I can easily convert to shorts). Unless it is raining, I usually wear a merino wool t-shirt, a heavier merino long-sleeve t-shirt, and start with a fleece. I keep in my pocket a thin merino skullcap, perhaps the handiest piece of clothing I have for thermoregulation. It only takes a little uphill hiking to get me out of the fleece. Once I reach hiking temperature, the subtle vital heat practices emerge. I sweat profusely when exerting myself, regardless of outside temperature, which is why I found McPhee’s discussion of Dick Cook telling. I soon find my undershirt soaked even if the rest of my body– hands and head– remain cold. Practice then includes putting the hat on and off, often in different ways (pulling it above or over my ears, or pulling it down over my temples). The same goes for my long sleeves, which I regularly pull away from my wrists, or back down over them. These adjustments continue throughout the day responding to terrain difficulty, altitude change, moisture, wind speed, and physical exertion.

Thoreau’s vital heat is initially not an abstraction to enable social critique, nor does it designate a passively stable system, even if our thermostats today invite us to believe that is the case. Rather, what he describes in “Economy” is a set of material gestures that dynamically unfold and constantly change over time, conditions demanding attention, care, and vigilance. Thoreau characteristically resists the quick leap from the material to the abstract or transcendental. Rather, he stays on the ground, in the weather, over time. Maintaining vital heat in the great outdoors demands living deliberately.


T. Hugh Crawford