High Altitude Mountaineering
When you climb up seriously high, you need some serious kit to stay warm, protected and comfortable. Start Naked! add a soft base layer next to your skin to keep your skin fresh and cosy. Next comes warm midlayers trapping layers of air to provide warmth. Your outer layer will be thick and provide protection from the cold, wind, rain, snow, ice, hail and anything else the mountain can throw at you. Finally complete you clothing with some vital accessories.
Start Naked---> Base Layer---> Mid Layer---> Outer Layer---> Accessories
The clothing next to your skin needs to be ‘wicking’ to transport sweat away from your skin to keep you dry and comfortable. Man-made fibres are generally better at wicking and are lighter, but natural fibers are generally better at resisting bacteria growth and keep their thermal efficiency even when wet.
Your base layer will consist of UNDERWEAR, SOCKS, and THERMAL TOPS and BOTTOMS.
UNDERWEAR: - Choose underwear that is lightweight and wicking to keep you comfortable and moisture free. The areas covered by you pants is an area prone to problems from bacteria growth so it is important to stay dry, especially if there is limited access to showers/baths.
Men/Those with Exterior Genitals- you will probably want underpants that are supportive without being too restrictive; excessive movement in this area can lead to chaffing and soreness but underwear that it too tight can increase sweating and feel more uncomfortable. Dual pouch underwear that keep your penis and scrotum separate can be a good choice, but check for comfort when wearing a harness.
Ladies/Those with Interior Genitals- You may find that your normally comfortable underwear is not up to the task whilst you are mountaineering and sometimes a different style, cut or fabric can be more suitable. There are no right or wrong with underwear and, often, practice and experimenting is the only way to find out what works for you.
A sports bra or supportive top (if required) can be very important to keep you comfortable, under-wires should be avoided as they can become problematic if wearing a chest harness or a heavy rucksack.
SOCKS: - This is a seriously important topic! Socks protect and cushion your feet against movement and pressure from the inside of your boots and helps to keep your feet warm and dry. If you do not have suitable socks then you can very quickly develop sores, blisters, and even frostbite; all of which could mean the end of your trip!
Socks should keep your feet warm, but without letting them overheat, and dry. Wool socks offer excellent foot protection from rubs and blisters and help to keep your feet bacteria free. However, they can loose some of their performance and become very heavy when wet.
THERMALS: - Thermal underwear (“Thermals”) are usually quite snug fitting, stretchy clothes you wear next to your skin. They come in many shapes and sizes but often in “tops and bottom”. Long johns are long underwear leggings which can be worn under trousers to keep you warm and wick away moisture, you can wear them with or without underwear, although more hygienic with. Thermal tops come in short or long sleeved versions. Vests are usually not recommended as the narrow sleeves over your shoulder can cause rubbing when wearing a rucksack.
It is advisable to have a "Clean" and "Dirty" set of base layer (sometimes referred to as Wet and Dry sets or Day and Night Sets). When out on the trail wear your dirty set, but change into your clean and dry set as soon as you've set up camp and are protected from the elements. This process can help keep skin in good condition and limit bacteria growth.
The Mid-Layer of clothing is everything you put on over your base-layer/underwear except the outer most layer. It's possible that clothing in the mid-layer, such as a thick jumper, may be interchangeable with outer layer depending on the environment. Mid-layers keep you warm and protected from the cold, but can also just be coverings such as a t-shirt. It should allow moisture (sweat) to transit from the base layer outwards.
Mid-layer consists of TROUSERS, TOPS, JUMPERS/FLEECES, JACKETS