Base layer
Water conducts heat away from your body 25 times faster than air so a quality base layer is vital. The fabric used generally is ‘hydrophillic’ which wicks away moisture from your skin to be picked up by the next layer or taken away by the wind. Of the various fabrics, polyester, polypropylene, polymide or merino wool are used in base layer construction.

Mid layer
The middle layer of clothing is designed to keep you warm when on the trail. This layer has to deal with the moisture transferred from the base layer, so it needs to wick that moisture away or absorb it without losing much of its insulation properties.

Insulation layer
Unlike a mid layer, which you use when active, the insulation layer is more ‘camp wear’ or ‘warm wear’ in low activity times. Time waiting at the crag, watching a clear starry night in Glen Feshie, or hoping for a bus in Cusco, is greatly improved when the wind is kept out and the warmth kept in.

Windproof smocks and jackets
For 90% of the time in the UK weather, most active outdoor people prefer just a windshirt and a base layer. These tiny seemingly flimsy products have changed the lives of everyone we know. Gone is the stuffy high humidity building up around your body under your waterproof. Once one of these is in your sack, you won’t know how you managed without it!

Waterproofs
This is the one occasion when you want to choose wisely and get the best value for money result. There is nothing worse than being caught in foul weather and for the first line of defence to let in water, either by bad design or poor features.

Headwear
Warm hats are great, some keep the weather out and have ear muffs to keep your neck warm and dry too but, they can be too warm! A chilly day walking and all of a sudden you find your head sweating and cold water running down your neck. So what do you do?

How we lose heat and why we should use technical clothing
In cold conditions we lose heat through a number of different processes, which if left unchecked will reach the point where the body loses heat faster than it can generate it. In temperatures below 25C the body will automatically lose heat, this will lead to a lowering of our internal core temperature, and if ignored, result in hypothermia and finally, death.

Water
Water is continually lost through the normal bodily functions of urination, excretion, breathing and sweating.

The amount of water lost through sweating dramatically increases when in hot conditions or during any kind of physical activity.

Hypothermia
Hypothermia occurs when the body loses heat faster than it can generate it, leading to a situation where the body core is unable to maintain sufficient warmth to allow the proper function of vital organs.
Wet, wind and cold are the key environmental factors that cause hypothermia. Any two of these is enough to start the cooling process in earnest.