What to carry on a UK hill walk

British hills are small, but the weather on them is not. The difference between a grand day and a cold, frightening one is usually what was in the bag. This list is what stays in ours for anything above the tree line, from a two-hour ridge to a full day on the Carneddau.

The things that never come out of the bag

• Waterproof jacket and trousers. Real ones, not a running shell. It will rain.
• A warm layer you're not wearing. Fleece or a synthetic insulated jacket. In winter, two.
• Hat and gloves. Yes, in July. Summits are ten degrees colder than car parks, before the wind.
• Map and compass, and the ability to use them. A phone is a wonderful map until it's wet, cold or flat. Carry the paper one, and know which way north is on the compass before you need it.
• Head torch. Short winter days and long summer ones both end in the dark eventually.
• Food and water, plus spare. A litre, a sandwich and a bar more than you expect to eat.
• First aid kit. Blister plasters, tape, painkillers, a bandage. Small.
• Survival bag or group shelter. A big orange plastic bag weighs nothing and turns a twisted ankle from a crisis into a wait.
• Whistle. Six blasts, pause, repeat. On the shoulder strap, not in the bag.

Worth carrying most of the time

• Walking poles. Knees will thank you on the way down.
• Gaiters in bog season, which in Wales is every season.
• A power bank for the phone, and the phone itself in a dry bag.
• Sun cream and sunglasses. It happens.
• Microspikes from November to April on anything high. Boots alone on hard snow are how people slide.

Boots

Anything with ankle support and a sole that grips wet rock. Trail shoes are fine for dry summer paths; they are not fine on a greasy ridge in October. Wear them in before the big day, and carry the blister plasters anyway.

Before you leave the van

1. Check the mountain forecast, not the one for the village. The Met Office mountain area forecasts and MWIS give wind speed on the tops, cloud base and freezing level. Wind over 40 mph on a ridge is a different walk.
2. Tell someone your route and when you'll be back. A note on the dashboard is better than nothing: "Two walkers, up Cadair via Minffordd, back by 5".
3. Know your escape routes. Where can you drop off the ridge if the weather turns?
4. Download the map area to your phone so it works without signal.

If it goes wrong

• Stop, get warm, get out of the wind. Put the spare layer on before you're cold.
• Work out where you are. A grid reference from the map or a locating app. Signal is better on the tops than in the valleys.
• Call 999, ask for the police, then ask for mountain rescue. Tell them where you are, what's happened, how many of you there are, and what kit you've got. They're volunteers, they're brilliant, and they'd rather be called early than late.
• If there's no signal, text. Register your phone with the emergency SMS service before you ever need it.

The rucksack

Thirty litres covers a day in summer with the whole list above. Thirty-five to forty in winter once the spikes and the extra layer go in. A rain cover is nice; a bin bag as a liner is better.

Pack the waterproofs and the warm layer at the top, where you'll get them out in a hurry. Lunch in the middle. The survival bag at the bottom, because with luck it stays there.

A rule we stick to: if the kit list feels like overkill in the car park, it's about right. If it feels about right in the car park, the forecast is bad enough to pick a lower hill.