Start With the Bag, Not the Kit

Most UK hill days come down to a single bag you'll carry for six or eight hours, so it's worth getting that right before you worry about what goes inside it. For a typical day on the fells, a 25 to 30 litre pack covers almost everything. If you're heading out in winter, carrying kit for children, or tackling a long Cairngorms plateau day, go up to 35 or 40 litres. Bigger than that and you'll fill it with things you don't need.

Fit matters more than features. Load the pack, then adjust the hip belt first — it should take most of the weight on your hips rather than hanging from your shoulders. Tighten the shoulder straps afterwards, then the sternum strap across your chest. A well-fitted pack feels close to your back and moves with you rather than swaying behind you on steep ground.

Before anything else goes in, line the main compartment with a dry bag or a heavy-duty rubble sack. A rain cover helps, but it won't save your spare fleece in horizontal Welsh rain. A liner will. Leave a bit of room, too: you'll shed layers on the way up and want them back on the summit.

The Kit That Earns Its Place Every Time

There's a core list that goes in the bag on every hill day, regardless of the forecast. The forecast is often wrong, and in Britain it can be wrong in four different ways before lunchtime.

• Waterproof jacket and over-trousers — packed, not worn, unless it's already raining. Over-trousers are the item people leave behind and regret most.
• A spare warm layer — fleece or synthetic jacket, kept dry in its own bag.
• Hat and gloves — even in July. Summits are cold, and a windy col saps heat fast.
• Headtorch with spare batteries — a late descent or an unexpected delay turns a good day into a serious one without light.
• Map, compass and a paper route plan — a phone is useful, but signal and battery are not guarantees.
• Whistle — six blasts, repeated, is the international distress signal. It weighs almost nothing.
• Small first aid kit — blister plasters, tape, painkillers, and any personal medication.
• Emergency shelter — covered in more detail below.

Food and Water: Fuel for the Climb

Water is the item people underestimate. Carry at least 1.5 litres for a half day, and two to three litres for a full day on the hills. Refill points above the valley are rare, and a mountain stream is not always the clean source it looks. If you sweat heavily, add an electrolyte tablet or a small amount of salt to one bottle — plain water alone won't replace what you lose.

For food, the rule is simple: bring things you'll actually eat when you're tired and slightly cold. Sandwiches, oatcakes with cheese, nuts, dried fruit, flapjack and a pork pie all work well. Eat little and often rather than saving everything for one stop. A flask of hot tea or soup is worth its weight in morale on a winter day, and it warms you from the inside when a break in the wind isn't available.

Keep one emergency ration permanently in the bottom of your bag — a cereal bar or two that never gets eaten on a normal day. It's there for the day that isn't normal.

Layers: Dressing for Four Seasons in One Day

The classic British hillwalking warning is that you can experience four seasons in one outing, and it's not an exaggeration. Dress in layers you can add and remove: a base layer, a mid layer such as a fleece, and a waterproof shell. Start slightly cool, add a layer before you get cold, and strip one off before you start sweating heavily. Sweat-soaked clothing chills you quickly the moment you stop.

• Spare gloves — a second pair, because the first will get wet.
• Spare warm layer — even when it's mild at the car park.
• Spare socks — invaluable after a bog, a river crossing, or a boot full of rain.
• Avoid jeans and cotton — they hold water and lose all insulation value.

Pack your spare layers inside a dry bag so they stay usable no matter what the weather does to the outside of your pack.

Emergency Shelter: The Item Nobody Wants to Use

This is the piece of kit that turns a difficult hour into a manageable one. A lightweight group shelter, often called a bothy bag, packs down small and gives two or more people a windproof, waterproof space to sit out a squall, treat an injury, or wait for help. If you walk alone, carry a personal bivvy bag or survival bag instead, plus a foil blanket as a backup.

Learn how to deploy it before you need it. The technique is simple: get it out of the wind, sit down, pull it over everyone, and tuck the edges under you. Once inside, eat something, drink something, and check your map and the conditions. A small foam sitting mat adds real insulation from cold ground and doubles as a bit of comfort at lunch.

Packing It So It Works on the Hill

How you pack matters as much as what you pack. Put heavy items — water, food, flask — close to your back and roughly midway up the pack. Keep the map and compass in a pocket you can reach without taking the bag off, not buried at the bottom. Water bottle accessible, snacks in a hip pocket, everything else organised so you're not rummaging with cold hands in a downpour.

Before you leave the car park, run a quick mental check: waterproofs, spare layer, hat and gloves, torch, map and compass, shelter, food, water. Leave a note of your route and expected return time with someone at home, and check a mountain-specific weather forecast rather than a town one.

The best kit list is the one you can carry comfortably all day. Keep it lean, keep it dry, and you'll be ready for whatever the hill decides to throw at you.