Cooking & heating without power

The deadly danger: understanding carbon monoxide

Carbon monoxide (CO) is produced in any combustion where there is too little oxygen – that is, precisely when a grill, a stove or a heater burns in a closed room. The gas is colourless, odourless and tasteless; you cannot perceive it with your senses. It irritates neither the eyes nor the airways, so there is no natural warning.

In the body, CO binds to the same sites on the red blood pigment as oxygen – and much more strongly. As a result, the blood is loaded with CO instead of oxygen, and the cells and organs suffocate internally. That is exactly why a high CO concentration can cause unconsciousness and death within minutes, and the time between the first symptoms and unconsciousness is short.

The first signs of CO poisoning are non-specific and easily misjudged: headache, nausea, dizziness, tiredness and drowsiness, later vomiting, shortness of breath and confusion through to unconsciousness. Because several people in the same room fall ill at the same time, that is an important warning sign.

For beginners: remember one single rule that prevents almost all accidents – nothing with a flame or an engine burns indoors. No grill, no portable gas stove in continuous operation, no patio heater, no generator, not even «just briefly» and not even with the window open.

Expert tip: a carbon monoxide detector (standard EN 50291 for the home) warns before dangerous concentrations build up – unlike a smoke detector, which does not detect CO. It makes sense wherever a flame is used for heating or cooking, especially with a fireplace, a wood-burning stove or a kerosene heater. However, it does not replace any of the rules of conduct; it is the last line of defence.

1. Get out into the fresh air immediately – those affected and yourself; if you would be putting yourself in danger, call the fire brigade first
2. Open windows and doors wide and leave the room (do not stay in it to air it)
3. Switch off the source of combustion only if that is possible without staying in the room
4. Emergency call: for severe symptoms or unconsciousness, ambulance 144; for advice, poison helpline 145 (Tox Info Suisse)
5. Place unconscious people who are breathing normally in the recovery position; if there is no breathing, start resuscitation immediately

How do I cook without power – indoors and outdoors?

The safest way to get through a power outage is with food that you can eat without cooking – bread and crispbread, tinned food, hard cheese, dried meat, chocolate, rusks, dried fruit. The federal government explicitly recommends such supplies that can be eaten cold in case the hotplates stay cold. That way you need no open flame indoors at all.

If you want to cook a hot meal, the open flame belongs outdoors: on the balcony, on the terrace or in the garden. A camping stove with a gas cartridge, a grill or a hobo stove does the job reliably. The Swiss Advisory Centre for Fire Prevention explicitly advises against using camping stoves indoors – because of the high risk of carbon monoxide poisoning. A yellow flame instead of a blue one is a warning sign of incomplete combustion.

The fondue burner also deserves respect: the main danger here is fire and deflagration. Fuel paste is considerably safer than liquid methylated spirit. Never refill a hot burner – there is a risk of explosion –, never blow out a jet of flame, and never leave the burning burner unattended. Ensure good ventilation.

For beginners: plan for a small portable gas stove with several spare cartridges and use it outdoors. That way you are independent of the cooker without putting yourself in danger. Do not forget a manual tin opener – electric ones do not work without power.

Expert tip: work out your gas requirement roughly. As a robust guide value, one litre of water needs around four to five minutes and in the order of 10 to 15 grams of gas to come to the boil – depending on the stove, wind and water temperature. A 450-gram cartridge thus provides very roughly three hours of burning time, or is enough for about 25 to 30 litres of water; a 230-gram cartridge about half that. For your supplies, calculate rather generously per warm meal and keep spare cartridges ready.

Fire safety when cooking outdoors

Clear distances apply outdoors too. A grill stands steadily on a stable base, and combustible material – furniture, parasol, hedge, house façade – belongs at least one metre away. A fire bowl or a fire basket needs more space: at least three metres' distance from anything combustible and never under a roof. Ash can glow for days; let it cool completely for at least 48 hours before you dispose of it.

There is no generally applicable Swiss minimum distance between open fire pits and buildings – here the duty of care applies: the larger the fire and the more wind, the greater the distance. In dry conditions, cantons can impose fire bans at short notice; find out beforehand.

For beginners: always keep extinguishing agents ready – a bucket of water or sand; for grease fires (burner, pan) never water, but a lid or a fire blanket.

1. Choose a spot outdoors, steady and sheltered from the wind, never under a roof or canopy
2. Remove anything combustible: at least 1 m for a grill, at least 3 m for a fire bowl/fire basket
3. Have extinguishing agents ready (water/sand; fire blanket for a grease fire)
4. Never leave a fire/stove unattended; keep children and pets away
5. Let ash cool for at least 48 hours before it is disposed of

How do I keep a room warm without power?

Without heating, the most effective strategy is to keep not the whole home warm, but one single small room. Close the doors to all the other rooms, seal gaps around the doors with blankets or towels, and insulate the windows at night with curtains, roller shutters or blankets. Everyone stays together in this room – body heat counts.

Against the cold on the body, the layering principle helps: several thin layers on top of one another, which trap insulating air, keep you warmer than a single thick garment. At night, a good sleeping bag and additional blankets are the best source of warmth. With sleeping bags, the comfort temperature according to the standard is the decisive figure when buying – not the extreme temperature, which only marks a survival limit.

Candles and tea lights are no good for heating. A tea light delivers only around 30 to 40 watts of heat, whereas a room needs a few hundred to over a thousand watts, depending on its size. The popular «tea light heater» with an upturned flowerpot does not physically generate any additional heat either – it merely redistributes it. It is dangerous all the same: fire brigades and chimney sweeps warn against it because tea lights standing close together can ignite one another and trigger a wax fire with a jet of flame, which – like a grease fire – cannot be extinguished with water.

For beginners: keep moving, eat and drink something warm (if it can be prepared safely), and put an insulating layer between yourself and the cold floor – a sleeping mat or a folded blanket. Put a hat on: heat is lost through every uncovered part of the body – the head gives it off roughly in proportion to its surface area (around 7–10 %), not disproportionately. The hat helps all the same, because the head is often the only uncovered part.

Expert tip: anyone who has a fireplace or a wood-burning stove has a real source of heat – but only if it is operated correctly. The chimney draught must be ensured at all times; it only builds up after a few minutes. If the air supply is throttled too early or too much, or if the chimney is blocked, the lack of air produces carbon monoxide, which can get into the living space. Never leave it burning unattended, never leave children alone in the room, and install a CO detector.

1. Choose one small room and close all the other doors
2. Seal gaps around the doors; insulate the windows at night with blankets/curtains
3. Huddle together – body heat and a shared room
4. Dress in layers, cover your head, insulate yourself from the floor
5. At night, into a sleeping bag (note the comfort temperature) and blankets
6. Warm drinks/meals only with food heated safely (outdoors)

Supplementary heaters with a flame: only with the greatest caution

Kerosene and catalytic heaters are sold as off-grid supplementary heating. They burn fuel in the room and thus carry the same basic danger as any open combustion: they consume oxygen and can produce carbon monoxide if combustion is incomplete. Anyone who uses them at all does so only with permanent ventilation (window open a crack), never overnight and not in the bedroom, and additionally with a CO detector. Safer and entirely free of exhaust gas is a portable power station with an electric heat source – or simply the «keep one room warm» strategy.

Safety note: this guide does not replace advice from the fire brigade or a fire prevention advisory centre. Combustion appliances without a flue do not belong in closed living rooms and bedrooms. If in doubt: no fire indoors.

1. Operate only in well-ventilated rooms – one window permanently open a crack
2. Never operate in the bedroom and not overnight / while asleep
3. Install a CO detector in the room
4. Keep a distance from anything combustible, set up steadily, never leave unattended
5. Use only the fuel prescribed by the manufacturer; never refill when hot

Swiss context: frost protection & electricity shortage

If the heating fails for a longer period in winter, there is a risk of frozen and burst water pipes. If a building remains unheated or unused for a longer period, you should close the main stopcock, then open all the taps so that the remaining water drains off, and drain pipes, fittings and appliances. Important: the heating's frost-protection setting alone protects only the radiator, not the pipes – so during a short absence, leave the heating running on at least setting 1. Additionally insulate exposed pipes.

Switzerland distinguishes between two outage scenarios. An electricity shortage means that power is available but scarce over a longer period; it gives advance warning and is managed by means of a four-stage plan of measures: first appeals to save, then restrictions and bans on consumption, after that quotas for large consumers and – as the last measure – cyclical grid shutdowns, in which sub-areas are each switched off for around four hours and then switched on again. A blackout, by contrast, is a sudden, large-scale grid collapse from one moment to the next. For cooking and heating, this means: in an announced shortage you can bridge the plannable shutdown windows; for a blackout you must be prepared at all times.

For beginners: a small supply of gas, warm clothing, sleeping bags and emergency supplies that can be eaten cold cover both scenarios. You do not need more than that to begin with.

Expert tip: use an announced cyclical shutdown to prepare hot water, charge batteries and heat up the living space during the power phase, before the next four-hour window begins. In this way you deliberately shift consumption into the supply phases.

Common mistakes

1. Putting a charcoal or gas grill in the home, cellar or garage – even «just briefly» or with the window open, it is life-threatening (carbon monoxide)
2. Using a portable gas stove in continuous operation indoors – the fire prevention advisory centre advises against it
3. Relying on a tilted window to protect against CO – it does not
4. Using candles or a «tea light heater» with a flowerpot to heat a room – it hardly heats and can trigger a wax fire
5. Operating a fireplace with the air supply throttled too early or with a blocked chimney (CO in the living space), or leaving it burning unattended
6. Running a kerosene/catalytic heater in the bedroom or overnight
7. Wanting to heat the whole home instead of keeping one single room warm and sealing it
8. Not shutting off the water during a prolonged heating failure in winter – frost damage to the pipes
9. Planning for a portable gas stove only, but no spare cartridges and no manual tin opener

Frequently asked questions

Official sources

• Advisory Centre for Fire Prevention (BFB) Fire prevention tips
• Tox Info Suisse Poison helpline 145
• Guide: Get through a power outage Basic preparedness without power
• Guide: Build an emergency supply Supplies that can be eaten cold as the basis
• Guide: MRE & emergency rations A warm meal without a cooker
• Scenario: Power outage When the power fails
• Scenario: Energy shortage Understanding planned shutdowns
• Emergency supply calculator Calculate food and water quantities for the household