Hiking clothes have to do three things well: release moisture from perspiration, prevent excessive heat loss, and shed rain water. A three layer system accomplishes this and more. The three layers are:
- Inner – wicks water away from skin
- Middle – wicks water away from inner layer and insulates
- Outer – wind and waterproof, yet “breathable”
The three layer system of hiking clothes intelligently coordinates multiple layers in response to a wide variety of temperatures and weather conditions. With three layers you can deal with both 85 F and sunny in the afternoon, and 28 F and snowy at night.
Heat generated from hiking acts as a pump, pushing moisture through these three layers. Traditional hiking clothing material, like cotton, and to a lesser extent wool, trap moisture. After a period of time, they can become completely wet and quickly suck heat away from your body.
All That Hiking Clothes Should Do and Be
Wick water away – Inner and middle layer, synthetic hiking clothing material is nonabsorbent (hydrophobic), yet has an open weave allowing the passage of moisture; some also have a water-attracting (hydrophilic) outer layer that pulls moisture from inside the garment.
Block out rain – Good, breathable rain gear is made of different types of materials that all function on the molecular level to repel water outside the garment and allow moisture to escape from within.
Block out wind – Any waterproof garment will be windproof, but a windproof garment is not necessarily waterproof. Some extremely comfortable windproof jackets are a good choice on some hikes because they are more breathable and much lighter than waterproof jackets.
Insulate – The middle, insulating layer of hiking clothes is usually wool or pile/fleece (polyester) that effectively traps dead air.
Ventilate – Middle and outer layers should have openings at the neck and waist to allow excessive heat and perspiration to escape. Otherwise moisture would be trapped inside the clothing. Good ventilation allows the release of much more moisture than wicking action.
Lightweight – Good lightweight hiking clothes can cut several pounds off your pack weight as well as the weight of the clothes on your body.
Durable – Hikers shimmy, scoot, roll, bump, crawl and scuff. Hiking clothes have to be strong. Who knows what capers you’ll engage on the trail?
Low in bulk – Freedom of movement is a sweet pleasure of good hiking clothes. Puffy clothing snags on bushes and branches with annoying frequency.
Quick Drying – Synthetic hiking clothes material is known as “drip dry.” This means you can wring them out when wet, shake them off, and still expect them to provide some warmth. No material insulates when wet, but new synthetics still function in emergency situations.
Easy to care for – Silk has a luxuriant texture. It is a decent inner layer, but has to be hand washed and dried flat over a long time period. Synthetic inner layers are much easier to deal with on the trail. You can wash them in a stream, shake them out, and expect them to be dry by morning. For convenience, all your hiking clothes should be able to go through a washer and dryer.
Inner Layer Hiking Clothes
Wet skin looses heat 75 times faster than dry skin. Well, that’s what I heard a guy on TV say once. But I believe it. Everyone has had the experience of stepping out of a hot shower into a cold bathroom. . .”Brrrr.” But as soon as you dry off. . .”Ahhh.”
So what’s happening? Conduction – the transfer of heat from one surface to another. Water conducts heat rapidly, while air conducts heat very slowly. So as soon as you dry your skin, you stop feeling chilled.
Inner layer hiking clothes, or “thermal underwear,” keep us warm by removing water from the skin as quickly as possible. It is made of synthetic materials like polypropylene, polyester, and chlorofiber. An open knit allows these materials to wick briskly, absorb less moisture, and dry overnight.
Underwear comes in 3 weights: light, medium, and heavy. Lightweight underwear wicks most quickly, and is best for summer hiking. Medium and heavy underwear are used for colder hiking when wicking is less important. Heavier underwear is best at insulating and less effective at wicking.
Underwear is meant to fit snugly to help trap air and make wicking faster, especially long underwear bottoms that are uncomfortable when baggy. Heavy tops should have a neck opening for ventilation.
Middle Layer Hiking Clothing
Pile is a fluffy, loosely knit polyester that wicks water, insulates superbly over a wide temperature range, and dries quickly. Fleece is a variation of pile with a denser knit fabric and smoother finish. These two terms are used interchangeably by marketers. Pile tops and bottoms are standard for the middle insulating layer.
Pile garments should be close fitting to trap air. Tops should have elasticized writs and waists to prevent cold air from bellowing in and pushing hot air out as your body moves.
Piles’ only weakness is its inability to block out wind. A strong gust on a cold day will chill you to the core. Windproof pile is available, but it doesn’t wick as well, is more bulky, and is very warm (too hot for moderately cold temperatures). A lightweight wind shirt is a better solution. The pile / wind shirt combination gives you the ability to deal with a wide variety of temperatures and weather conditions.
Lollygagging and goofing off around the campsite produces little body heat. In cold conditions, you may need a heavy insulating layer. Windproof pile is good for this purpose.
Nothing beats the insulating power of down. It’s lightweight and compressible, making it an easy choice for backpacking. At rest stops and camp sites it beats off the cold like sunshine. But it is useless as a middle layer for hiking because it soaks up sweat like a sponge.
Outer Layer Hiking Clothing
Windproof, waterproof and breathable fabrics like Gore-Tex and Sympatex materialize the outer layer or “rain gear.” Breathable raingear functions very well for short, light rains. You can expect to get at least a little wet in heavy rains. For rains lasting days several days, you may need to find some shelter to dry out completely.
Raingear, also referred to as outer shells, comes in tops and bottoms. A parka-style top with a zipper is generally the best choice because it is easier to put on, especially in the rain, than a pullover shell. Rain pants provide an easy freedom while walking in the rain, but can be very hot and sweaty with little ventilation.
Other, less popular, raingear:
Umbrella – Lightweight backpacking umbrellas are brilliant for day hiking in light rains without wind. They are also an excellent first line of defense used in conjunction with raingear on long wet trips.
Poncho – Made of a waterproof, non-breathable sheet of material, approximately 4’ x 7’. Ponchos cover both you and your pack. They are completely ventilated – which is a flaw under high winds.
Trash Bags – An effective, short-term solution. Two bags form an entire suit: a head hole in the bottom of one makes a shirt; cut the bottom out of the other, step through and tie it around your waist for a skirt.