Clothing and Equipment

March 8, 2000 Byron Smith gives a show-and-tell of the equipment he will be using and the clothing he will be wearing at the summit.

Below, you'll find a description of Byron's clothing and an overview of how the use of layered fabrics will help protect him from the elements. Once the packing list is complete, visit this location for a list of expedition equipment.

Clothing

The Base Layer

Staying dry on the inside is just as important as staying dry on the outside. The first layer, next to skin, is usually referred to as the dry layer. When you are climbing your body generates heat and cools by perspiring. It is crucial to wick this moisture to an outside layer where it can be evaporated away. Effective moisture transfer and evaporation reduces heat loss and reduces your risk of hypothermia. Next to his skin, Byron will be wearing long underwear, made of polyester fibres that will transfer this excess moisture to an outside layer.

The Thermal Layer

Heat from the body is also lost through conduction. The next layer, the thermal layer, helps prevent heat being conducted away from your body. Worn in combination with the dry layer, its function is to produce a warm layer of insulation.

Traditonal materials for insulating layers are wool, pile or down. Now synthetic fabrics are often chosen because they're made to be light-weight as well as insulating. Each of these materials provide space for dead air which is warmed by the body to produce a layer of insulation.

The denser a material, the faster heat can be transfered by conduction. Air is much less dense than a piece of fabric, so less heat is conducted through a layer of air. It's not the clothing that keeps you warm, it's the dead air trapped by the clothing.

At lower elevations (below 23,000 ft or 7,010 m), Byron will be wearing Polartec fleece pants and shirt as his thermal layer.

Polartec is a synthetic material made of polyester fibres that have been brushed on both sides. The brushing produces tiny pockets that trap air which is then warmed by your body to produce a layer of insulation.

Along with providing insulation, the polyester fibres also help to pull moisture to the surface for quick evaporation. Polartec fleece is lightweight, quick drying and compactable. These features are important because Byron will be packing and wearing his gear over a three-month period. Since there are no washing machines or dryers on the mountain he'll want clothing that's quick drying and won't hold perspiration.

At higher elevations, from Camp III and up, where the temperatures are extreme, Byron will abandon his fleece layer for a down layer. He will be wearing a one piece down suit. Down is nature’s warmest insulator. Like the fleece, the down provides tiny pockets of air that are heated by the body to produce a layer of insulation. Down is known for its high heat retention and superior thermal properties. Because of its high warmth to weight ratio and compactability, down is the perfect choice in these conditions.

The Outer Protective Layer

The outside layer is a climber's first line of protection against the elements. Byron will have a variety of shells to choose from to wear alone, or in combination with the other two layers, depending on his activity level, the temperature and weather conditions.

The main function of the shell is to protect against wind, rain and snow while allowing moisture to be transferred to the outside, for quick evaporation. Byron will be wearing Gortex fabric as his outer layer, either as a one piece suit, a two piece shell jacket and pant or a lightweight shell jacket and pant.

Gortex is a windproof, waterproof, breathable fabric that is made up of micropores that are too small to let wind, snow and rain pass through, yet large enough to allow moisture molecules to escape.

This is an important layer in keeping a climber warm and dry. If clothing gets wet from perspiration trapped on the inside, or from moisture from the elements outside, you'll become uncomfortably cold because of accelerated heat loss caused by wet conductive heat transfer. Heat is lost 23 times faster by wet conductive heat transfer than by dry conductive transfer.

Heat can also be lost by convection. Convective heat transfer is caused by the movement of air. An example of this is the chill you feel when a draft of wind blows away the warm layer of insulation around your body. The shell, or outer layer, can help protect your body from the wind, keeping the trapped air inside.

Another important feature of all outer shells is plenty of zippers for ventilation. Layering garments that can be easily removed, added, ventilated, and which can transfer moisture and protect you from the elements is the most effective way to control the environment, keep you comfortable and help you to stay alive.

Other Clothing

A high percentage of heat is lost through your extremities (head, hands and feet). On his head, Byron will be wearing either a fleece headband or a lined Polartec fleece cap. The cap will insulate Byron's head and keep wind out while the headband will provide warmth while allowing moisture to evaporate out.

For gloves, he will be wearing a combination of liner gloves, wind block gloves, glove shells and down mitts. On his feet he will be wearing insulated Everest One Sport boots.

BACK TO: Top