This all leads us (so neatly, its almost like we planned it!) to what kit to take. This decision is very personal and a lot of it will come from experience. Expect to take too much the first time you head out and then whittle it down to what you actually need and use (in addition to those just-in-case extras).
A couple of good starting questions when deciding what kit to take are:
How long am I planning on being out?
How long will it take for someone to reach me if it goes wrong?
How badly will this reflect on me when they find my body?
If the answer to the first two is: half an hour and about 5 minutes, then you can probably leave the emergency shelter at home.
But if you are heading far from the road and into the high hills, you need to consider the above questions very carefully.
Clothing: As with your route choice, the speed at which you able to move will influence what you will want to wear. Soft snow and high winds will see you moving much slower and so not generating as much heat as when moving quickly but then slogging up a snowy slope can see your temperature rise as you put way more effort than usual into your forward progress.
In winter, the difference between your temperature when moving and when static is most pronounced. A layering system that is perfect while moving quickly could see you dangerously exposed if you had to stop for any reason.
Spare layers are an essential back up in winter mountains but think about which you take. Are you likely to strip to the skin to change your baselayer, even if it is soaked, or is it better to carry additional midlayers that can be added under a shell, in addition to insulation? The weight penalty of carrying an extra midlayer is far outweighed by not getting hypothermic.
Insulating pieces are not normally part of the running arsenal, except when back at the car or overnight camp but in winter; insulation pieces can form an important part of your clothing system. The main choice in insulation is between synthetic or down fill; down is warmest for its weight and pack size but loses its insulating properties when wet; synthetic insulation is more durable than down and keeps its warmth even when wet but is slightly heavier and bulkier. Insulation pieces are often not as breathable as fleece or polyester layers and so you will need to consider this when using them. They are often best kept in the pack until you hit the tops or slow down later in the day.
It is tempting to layer up at the car, when you are cold and static but as soon as you set off and hit the first uphill, you will rapidly overheat, soaking your baselayer with sweat and will probably need to stop to take off a few layers. The old adages; ‘dress for 15 minutes time’ and ‘be bold, start cold’, really do still hold true.
Baselayers are still an important consideration in winter. Though you may be moving slower over some sections, there are also going to be parts that make you sweat, especially fighting wind and snow. If your baselayer does not wick away sweat or dry quickly, you will soon get cold and wet. Use a quick-drying layer that will respond to a variety of outputs throughout the day.
Even in relatively benign conditions, if there is snow on the ground or it is saturated with winter rain and meltwater, it is likely your socks and gloves are going to get wet and cold. You should always think about carrying spares of both (it is quite normal to head out with 3 pairs of gloves). It may also be worth looking into waterproof socks, though they may not keep you 100% dry, they tend to be much warmer than alternatives. This is also a good time to give mitts a shout out. Keeping all your fingers grouped together means they’ll be a lot warmer than in just gloves. An overmitt allows you to swap and change gloves then cover everything up and keep them warm and dry, leaving fingers free when needed.
See below for our ideal winter layering system along with the rest of our winter kit list.