You set off for a day on the fells with a light rucksack and a reasonable forecast. By mid-afternoon the cloud is down, the wind has turned, and the path you wanted is a bog. A tweaked knee, a slower companion or a missed last bus turns a day walk into something else. The bothy marked on the map is suddenly not a curiosity but a plan. An emergency bothy night is not a planned overnight. It is a cold, dark, improvised stop in a basic shelter, and the kit you carry for a normal day can make the difference between a shivery vigil and a manageable night.

Pack for the night you did not plan

Every day rucksack should carry a small emergency overnight pouch. Not a full camping kit, just enough to keep you warm, fed, lit and sheltered if the day goes wrong. Packed carefully, it adds perhaps 1.5 to 2kg. If you never use it, that is a small price. If you do, it turns a bothy from a windbreak into a refuge.

• Keep it together: use a dry bag so spare layers, food and torch stay dry even if your rucksack is soaked.
• Know your bothies: check the map before you go. Some have fireplaces and sleeping platforms; many have nothing but four walls, a roof and a draught.
• Tell someone your plan: an emergency bothy night is safer if someone knows where you are and when to raise the alarm.

Spare layers and waterproofs that actually work

In a bothy, damp cold is the enemy. Wet clothing pulls heat from your body, and a stone floor does the same. The goal is to arrive, strip off wet things, and get into dry insulation quickly. Cotton is useless here: it holds water and chills you. Choose synthetic or merino layers that keep working when damp.

• Spare base layer: a long-sleeved synthetic or merino top and leggings, kept in a dry bag.
• Insulated mid-layer: a synthetic jacket or fleece that stays warm when damp. Down is warm but loses loft when wet, so treat it as a luxury, not a survival layer.
• Waterproof shell: jacket and trousers, even if the forecast is good. They cut wind and keep you dry on the walk out.
• Warm hat and gloves: a spare pair of gloves and a hat make a surprising difference when you are sitting still.
• Spare socks and a lightweight bag or bivvy: dry feet prevent cold and blisters. A summer-weight sleeping bag or emergency bivvy bag adds real warmth if you have room.

Food, water and a hot drink

Bothies often sit near a stream, and upland tarns look temptingly clean. Assume all water is contaminated. Carry treatment tablets, a filter or a stove and fuel. A hot drink is not just comfort; it is warmth from the inside. A vacuum flask of tea, coffee or soup is one of the best emergency items you can carry.

• Flask: fill it before you leave. Even a small flask can lift morale and raise your core temperature.
• High-energy food: aim for at least 1,000 to 1,500 kilocalories of no-cook food. Nuts, dried fruit, chocolate, cereal bars, oatcakes and cheese all work.
• Water treatment and a small stove: tablets, drops or a filter. If you boil water, bring it to a rolling boil for at least a minute. Never rely on the bothy fire.

Light, shelter and the small kit that saves the night

Darkness changes everything. A head torch lets you find the bothy, sort your kit and move safely outside. An emergency shelter is not just for summits; it can keep you warm if the bothy is full, locked or unusable. Small items weigh little and solve big problems.

• Head torch and spare batteries: a hands-free light is essential. Pack spare batteries or a charged power bank and cable.
• Emergency shelter or bothy bag: a lightweight group shelter traps warmth. A foil blanket or emergency bivvy bag is a smaller backup.
• Closed-cell foam mat: a short length insulates you from a cold floor and doubles as a sit mat. It weighs almost nothing and makes a huge difference.
• First aid kit: include blister plasters, painkillers, a small dressing and any personal medication.
• Whistle, map, compass and phone: electronics fail. Know how to navigate to the bothy and back out again. Keep your phone warm and save battery.

Using a bothy and tarn water sensibly

Bothies are open shelters, not hotels. They can be full, dirty, cold and draughty. If you arrive late, be quiet, be considerate and be prepared to share. Do not rely on a fire. Many bothies have no safe fuel supply, and collecting dead wood can damage fragile upland habitat. Use your stove if you have one, and ventilate the room.

• Treat all water: upland tarns and streams can carry animal waste and microorganisms. Filter, treat or boil.
• Ventilate if using a stove: carbon monoxide can build up silently. Keep a window or door open and never use a stove to heat a sealed room.
• Leave no trace: take all rubbish home, including food scraps and tea bags. Bury human waste 30cm deep and at least 30m from water.

An emergency bothy night is rarely comfortable, but it can be safe. The difference is what you carried without thinking: a dry spare layer, a flask, a torch, a shelter and enough food to keep going. Pack those few things on every upland day, keep them dry, and you will never be caught out by a night that was not in the plan.