What goes in the pack on a winter mountain day

• Things you will use — Food, water, gloves, hat, shell, warm layer, map, compass. These come out during the day and go back in, and they should be packed where they can be reached without emptying anything.
• Things you will use if the day goes long — A head torch with working batteries, spare gloves, more food than the plan needs. Cheap in weight and the difference between an inconvenience and an incident.
• Things you carry so you never need them — A group shelter or bivvy bag, a first aid kit, a whistle, a means of calling for help. Carried on the understanding that the day you leave them is not predictable in advance.
• Things specific to the ground — Axe, crampons, rope, helmet, harness. These are decided by the route rather than by the season, and carrying them without knowing why is a sign the route has not been thought about.

A head torch is the most commonly omitted item and the most consequential. Winter days are short, plans slip, and the difference between descending in the dark with a torch and descending in the dark without one is the difference between slow and serious. Carry it every winter day regardless of the plan, and check the batteries rather than assuming.

Spare gloves are the second. Gloves get wet, wet gloves in wind stop working, and hands that have stopped working cannot operate a zip, a buckle or a phone. Two spare pairs is not excessive on a long winter day and weighs almost nothing.

A group shelter is the third, and it is the one people find hard to justify until they have used one. It is a lightweight nylon bag that a party sits inside, and it turns a stop in driving wind into somewhere a casualty can be looked at, a map can be read, or a cold person can recover. It is the single most effective piece of emergency equipment for its weight in temperate mountains.

Order matters more in winter than summer because you will be opening the pack in wind, possibly in gloves, possibly on a slope. Shell and warm layer at the top, so putting them on is not an excavation. Emergency items at the bottom, where they will not be pulled out by accident. Anything that must not get wet inside a dry bag, because a pack cover is not waterproof and neither is most of the pack.

The axe goes on the outside where it can be reached before it is needed, not after. Crampons go in a bag or a pouch — loose points shred everything they share a compartment with, including the shell you will want later.