There's a moment on every cold fell walk when you realise your clothing is either working brilliantly or making you miserable. The difference usually comes down to layering. A single thick jacket might feel cosy in the car park, but ten minutes into a steep climb you'll be overheating, and by the summit you'll be chilled through. A flexible system of base, mid and shell layers lets you fine-tune your temperature minute by minute. Here's how to build one that works on British hills, from a damp November morning in the Peak District to a windswept Cairngorm plateau.

Start with a base layer that moves sweat away

Your base layer's job is simple: move moisture away from your skin so you stay dry. When you sweat and then stop, wet fabric pulls heat from your body fast. Cotton is the enemy here — it soaks up water and stays cold and heavy. Choose merino wool or a synthetic fabric like polyester. Merino feels lovely against the skin, resists smells, and works well in cold, dry conditions. Synthetics dry faster and are cheaper, making them ideal for wet, dreich days.

• Lightweight: best for hard climbing or milder cold. Dries very quickly.
• Midweight: good for winter walking and slow-paced days on the tops.
• Fit: snug but not restrictive. It should touch your skin to wick properly.

Pack a spare in your rucksack for multi-day trips. Putting on a dry base layer at camp or in the car park transforms how you feel.

Add a mid layer to trap warmth

Mid layers are your insulation. They trap air heated by your body. The key is to have more than one option so you can add or remove as your effort changes. A fleece or lightweight synthetic jacket is the classic choice. Fleece is breathable, cheap and hard-wearing. Synthetic insulation is warmer for its weight and works even when damp. Down is warmer still but loses its loft when wet, so it's best saved for dry, cold days or camp.

• Thin fleece or grid fleece: for active climbing when you need just a little warmth.
• Midweight fleece or synthetic jacket: for stops, gentle descents and cold valley starts.
• Spare dry layer: keep a synthetic or down jacket in a dry bag for emergency use.

Don't wear your warmest mid layer from the start. Begin slightly cool and add a layer after ten minutes, once your body has warmed up.

Protect yourself with a shell layer

British fells are famous for wind and rain that arrive sideways. Your shell layer — a waterproof and windproof jacket, and often trousers — is your defence. Wind strips away the warm air your mid layer has trapped, so even a light breeze can chill you quickly. A good shell has taped seams, a hood that fits over a hat, and pit zips or chest vents so you can dump heat without removing the jacket.

Softshell jackets are another option for dry, cold, windy days. They breathe better than hardshells and stretch as you move, but they won't keep out sustained rain. For most UK winter walking, a hardshell is the safer bet.

• Check the hood: it should adjust and stay up in gusts.
• Pit zips: essential for regulating heat on steep climbs.
• Waterproof trousers: easy to forget, but they keep wind off your legs and let you sit down on wet ground.

Manage layers as you move and stop

The art of layering is not just what you wear, but when you change it. On a steep climb, you'll generate a lot of heat. If you wait until you're sweating heavily, you've already soaked your base layer. Instead, remove a mid layer or open your shell's vents before you start to overheat. On a summit stop, the moment you stop moving, your heat production drops. Put on your insulated jacket and hat immediately, before you feel cold. Eat and drink while you're layered up.

• Start cold: begin the day slightly chilly; you'll warm up within minutes.
• Adjust early: take off a layer as soon as you feel clammy, not after.
• Stop smart: add insulation before you stop, not after you're shivering.

Practise this rhythm on short walks. It soon becomes second nature, and you'll stay comfortable instead of swinging between sweating and shivering.

Fine-tune for British conditions

British weather is rarely extreme, but it changes fast. A still, grey morning can turn into a windy, wet afternoon on the tops. Your layering system should be adaptable enough for that. Pay attention to your extremities too: a warm hat, gloves and a neck gaiter make a huge difference. Your legs need layering as well — walking trousers with a wicking base layer underneath, plus waterproof over-trousers, work well in winter. Finally, pack your layers so they're easy to reach. A rucksack with a top pocket or side straps lets you grab gloves or a hat without stopping for long. Keep a dry bag for your spare insulation, and remember that a wet shell can be shaken dry and put back on. With a sensible system, you'll stay comfortable from valley floor to summit, whatever the forecast throws at you.