The invisible danger in your tent: carbon monoxide

Most fatalities in camping are not caused by avalanches or falls. One of the causes near the top of the statistics is simpler and much quieter: carbon monoxide poisoning.

Why tents in particular

Carbon monoxide (CO) forms wherever fuel burns incompletely — a gas stove, a petrol burner, a charcoal grill, even a fire that is dying down. Its danger is not in its chemistry but in the fact that you cannot detect it: it is colourless, odourless and tasteless. It does not make you cough like smoke or sting your eyes. Your body mistakes it for oxygen and loads it into the blood instead.

A tent is the perfect box for this. What does a person do on a cold night? Close every opening to keep the wind out. Air circulation stops, and within minutes the CO inside reaches a dangerous level.

The three most repeated mistakes

1. Cooking inside the tent. Pulling the stove into the vestibule because it is raining counts too — the vestibule is also an enclosed volume.
2. Lighting a stove "just to warm up". A gas stove is not a heater. It was never designed to heat a tent and this is the single riskiest scenario.
3. Bringing an extinguished grill inside. Glowing charcoal releases CO without any flame — in fact it releases more.

The first sign of poisoning is drowsiness and a headache. That is the problem: people read it as tiredness and go to sleep. And nobody rescues themselves in their sleep.

What to do instead

• Always cook outside the tent. If it is windy, build a screen on the leeward side with rocks or a backpack.
• Keep two points of airflow while you sleep — one low, one high. A single vent is not enough; circulation needs an inlet and an outlet.
• Get your warmth from clothing and your sleeping system: a season-appropriate bag, an insulating mat and dry socks work far better than any stove. Cold coming up from the ground is the real problem at night.
• If anyone in the group complains of a headache, nausea or unexplained drowsiness — get them out into fresh air immediately. Move first, discuss afterwards.
• If you camp in winter regularly, buy a small CO detector. It fits in your palm, costs little and wakes you with an alarm.

Fuel choice matters too

Small gas stoves (butane/propane mixes) produce little CO when burning properly, but in cold weather the pressure drops, combustion becomes incomplete and CO output rises. Petrol and alcohol stoves are more reliable in the cold — at the cost of more smoke and smell. The rule does not change for either: outdoors.

For your first winter camp, going with an organised group rather than alone is the smartest start — the gear is provided and the overnight setup is built by someone who knows how. One such format is Qusar Lazy Camp; a gentler option is Hamoşam mountain camp.