Activities like biking, kayaking, camping, hiking, and long-range trekking all require the adventurers to be very well prepared, especially when it comes to clothing. In many circumstances, layers can literally mean the difference between life and death. You don't want to be caught in harsh conditions at high altitude without the proper gear. Here are some layering guidelines to help you plan your next expedition. You will want to be equipped with a base layer, middle layer, and outer layer no matter the temperature.Base Layers
Base layers are arguably the most important because they are designed to keep moisture away from your skin so that you don't get chilled. This technique is called "wicking" the water off your body. Thinner base layers actually wick the sweat better than thicker layers, and they also dry faster. Wearing a thin, synthetic t-shirt will move the moisture to the outside of the clothing and allow your body to regulate its temperature without feeling cold. Popular fabric options for base layers generally include synthetics like nylon and polyester, or better quality natural fibers like silk and merino wool. Wool can actually absorb up to 33% of its weight in water, keeping moisture well away from the skin. Plus, damp wool is a great insulator. It also conveniently prevents odors from getting trapped in the material. There is a wide range of base layer weights often under the categories ultralight, light, medium, heavy, and expedition.Middle Layers
Middle layers are meant to properly insulate and retain body heat. You will want to choose between polyester fleece, synthetic insulated jackets, and down insulated jackets. Fleece is great because it dries quickly, but it doesn't offer you much protection as its breathability allows the wind to blow through. You'll need to layer it with a shell to block the wind. Synthetic insulated jackets are designed to mirror the heat retention capabilities of down jackets, and they do a good job of deflecting rain and wind, but they don't condense as well as the down. Down jackets are superior in the fact that they offer the most warmth for their weight and they are very easy to compress. They don't insulate as well if they get wet, so you should always have a shell to layer if you experience snow or rainy conditions. Generally, when it comes to jackets, the puffier they are, the warmer they are.Outer Layers
Outer layers are, of course, for rain, wind, and snow protection. From waterproof to water-resistant, and breathable to non-breathable, the wide range of shell options will surely provide you with the material and design you're looking for. The most versatile and most expensive choice is the waterproof, breathable shell. This option makes sense for all weather conditions and is usually the most durable.Hot Weather Layering Suggestion
Base layer: A short-sleeve synthetic tee to keep you dry, and a convertible nylon hiking pant with a mid-leg zipper that allows the pants to change into shorts.
Outer layer: A lightweight windbreaker. A breathable one is preferable.Cold Weather Layering Suggestion
Base layer: A mid-weight long underwear for both the upper and lower body. If possible, find a long sleeve with thumbholes to properly protect your hands and prevent drafts from blowing through the opening between your sleeve and glove. Generally speaking, for cold weather environments, it's optimal to have the least amount of skin showing as possible.
Middle layer: A quarter zip jacket followed by a puffy jacket with synthetic insulation, and mid-weight fleece pants. If possible, try to have at least one jacket with a hood. A helpful tip when layering jackets is to try to stagger your zippers. Avoid stacking them on your neck, which can cause uncomfortable rubbing and cause discomfort. Instead, make sure to mix and match with a crew neck and a neck gaiter.
Outer layer: A windbreaker or waterproof, breathable rain jacket accompanied by a thicker pant. You can add a hat and gloves depending on the specific climate.Rainy Weather Layering Suggestion
Base layer: A lightweight polyester long underwear for both the upper and lower body.
Middle layer: A lightweight fleece jacket and lightweight, synthetic hiking pants.
Outer layer: A lightweight, breathable, waterproof rain jacket or windbreaker, and waterproof pants to deflect the droplets. You can always add a hat for extra warmth.Benefits of The Layering System
What's great about layering your clothing is that you will be prepared for any sudden changes in climate. The sun may be out when you first set out on your adventure, but that doesn't mean that it will stay out the whole time. In cold weather climates, you will need multiple tiers of insulation to keep you protected from the elements. A good rule of thumb for layering is that it's always better to have too many layers, than not enough. That's because you can easily shed outer layers to cool yourself down, but you can't put on layers that you don't have if you need to warm yourself up. Leaving on an expedition underprepared can be lethal in certain conditions, so always make sure to cover all of your clothing bases. You will also need to take into consideration your expected exertion level before you pack for your trip. This will give you a better idea of just what kind of layers you need to bring. If you will be more stationary on your journey, you will obviously need to account for more layers and thicker material depending on the specific temperature. If you're planning on a high level of exertion, you may want to consider gear that's more lightweight so that you don't have to waste unnecessary energy. Either way, you should spend an appropriate amount of time accounting for your gear relative to the weather.