Modern-day Insulation

But modern man is probably less well adapted for living in extremes than his ancient ancestors who were toughened and acclimated to a degree of heat and cold exposure which modern man has been clever enough to avoid. In today’s jet age we can travel to extreme variations of climate in mere hours.

It takes an average person who works in a controlled atmosphere approximately two weeks to become acclimated to an new environment. My own experience has shown this to be true. When leading a trip, I find it is easier to sleep on the fifth and sixth day than the first four days because I have come from a controlled environment. I generally try to acclimate myself prior to a trip by opening the windows and sleeping without blankets.

Yet people who work in the outdoors and are continually subjected to the cold or heat can still maintain dexterity under these conditions. For instance, fishermen, loggers, and construction workers suffer few effects from being exposure to the weather to which they are accustomed; but they also dress suitably for their exposure.

I experienced this acclimation in the Bitterroot valley of Montana during one particularly cold winter. From late winter to spring temperatures were well below zero. At first I bundled up when I went to the wood pile. With each successive week the extremes seemed more bearable, until after a month of this activity I found myself checking the thermometer because it felt warmer than it actually was. By April, when it warmed up to 10° F. I was in my shirt sleeves.

Lacking the time to acclimate, the answer is insulation. According to the Oxford American Dictionary, to insulate is: 1) to cover or protect with a substance or device that prevents the . . . loss of heat; 2) to isolate from influences that might affect it. The key word being “affect.”

Try this experiment next time you play couch potato: lay a single open sheet of newspaper over you. Within seconds you can feel the warmth generated from your body. You can easily see that doesn’t take much insulation to stay warm if it is the ‘right’ insulation (remember, paper is a ‘natural’ product). Actually, anything in nature that works can be used as insulation: in addition to the down from birds, wool, and animal fur there is plant seed “down” (the fluffy seed pods of various plants), bark, grass, leaves and plant stalks.

We humans can take a lesson from the animal world as we see small creatures insulate their burrows with grass and fur. Birds use fibers and feathers to soften their nests before laying eggs, and insects build elaborate habitats with mud and bits of grass. What makes them so effective is that wool, fur, feathers and down, have a wonderful loft-they trap great quantities of air which in turn capture and retain body heat. Today, the modern search for a better insulation is driven by the attempt to “out-loft” nature.

But there is no insulation–natural or man–made-that is lighter, warmer, or softer than down. Down is the soft, shaftless clusters culled from the breasts and underbellies of geese and ducks. Each cluster is shaped like a ball, composed of thousands of fibers growing out of a central point. Feathers have shafts and are curved. Both feathers and down create a natural protective shield from the elements. They keep ducks and geese warm, even in the coldest climates by creating pockets of trapped air which insulate the birds. The colder it is, the harder your body works to produce heat, therefore more heat is trapped by the clusters of down, keeping you toasty warm.

Granted, down looses its loft when it gets wet, and some people believe that it also loses its insulating power when it is wet. Yet it takes down longer to get saturated than it does synthetics; its natural oils shed water and act as a built-in repellent. The main problem is quick drying: down simply does not give up water as easily and quickly as man-made fibers. However, in giving up water slowly, it preserves important body heat and energy.

So what do today’s manufacturers of insulative material try to duplicate? According to a report by Dr. Fred Fortess, director of apparel research at the Philadelphia College of Textiles and Science, a single gram of wool gives off 27 calories of heat when it goes from dry to wet; as wool absorbs moisture from the air, the fibers liberate heat. This is a characteristic of wool that scientists have been trying to improve in synthetic fibers.

Du Pont claims their Micro-loft insulation offers “down-like” comfort. All manufacturers show charts and graphics that compare their products to the insulating ability of down and most fall short of achieving the fill power of down. (Fill power is a rating of down’s quality as measured by its lofting ability. One ounce lofts to a maximum of 700 cubic inches.)

It is a difficult challenge: cut the wind and retain the warmth without getting all steamed up inside. Add to the challenge by wanting maximum performance and minimum weight. Yet nature’s miracle insulators can meet many of these requirements.

The most common and profuse types of seed down come from cattails, thistles, milkweed and cottonwood. And, since some species of these plants grow all over the continent, I’m sure you can find at least one of them in your area. Other plants also yield seed “fluff” but it takes longer to collect in quantity, therefore is less energy effective. One disadvantage of seed down to duck or goose down is that it is seasonal.

Milkweed, thistle and cattail seeds ripen in late summer. Occasionally you can find cattail seed heads during the winter months that are still intact, and sometimes even into the following spring. But the wind, rain and snow generally strip thistle seeds by early fall and the dry pods of milkweed open completely to release their seeds to the ground. You can generally find large clumps of cottonwood seed pods on the ground in the early summer, but rain quickly flattens them, destroying the insulating properties.

The good thing about cattails and milkweed pods is that you can collect and store the entire seed head or seed pods before they explode and have a good supply all winter. Just remember . . . these are seeds and stored seed heads and pods attract critters looking for food.

Because it is easy to collect and often abundant, cattail down can be very useful in a variety of ways. First, it provides everything you need for a cozy bed. But don’t sleep directly on the down because it gets into your mouth and nose and activates allergies. Instead, contain it between layers of cattail leaves, grass or bark. The insulation above you keeps it’s loft, that below you gets compressed, so add extra layers between you and the ground where you intend to sleep.

You can also stuff seed down into socks, pant legs, gloves, or wrap some in a bandanna and use it for a headband or hat. But remember, too much of a good thing isn’t always better. If you compact the down into your clothing, it restricts air flow and actually reduces the insulating effect. Your goal should be to provide a loose layer of insulation to trap body heat.

Unless your shoes or boots are exceptionally large, the best way to take advantage of seed down to warm your feet is to make a “bootie” by filling the space between two socks. Booties are great to wear around camp, for sleeping or for intermittent periods to warm feet on the trail.

I once made a cattail down vest from two shirts sewn together with yucca fiber and stuffed with approximately 17 cattail heads. It was comparable to a duck down garment for warmth and only slightly heavier in weight. We also made our son a cattail-down sleeping bag from his wool survival blanket and he used it for many moons, even after the down went flat. But that is the main problem with seed down, it is not as resilient as bird down-after a few weeks of use it should be replaced. Of course it can’t be washed without destroying the loft, and it tends to “mat” if it gets wet.