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Beware of the 'Silent Cold-Weather Killer': Carbon Monoxide

My fellow NOLS WMI instructors and I regularly provide wilderness medicine training to people interested in outdoor careers and outdoor recreation. But, recently, some related urban news caught my eye.

Following Hurricane Sandy, emergency rooms in New York and other affected areas saw a significant rise in the number of people seeking treatment for cold exposure and hypothermia. Given the storm's impact on people's homes and basic services, this is not surprising since so many residents were suddenly forced to "winter camp" without warning or preparation. Certainly our hearts, best wishes and donations go out to everyone impacted by the storm.

winter cooking

Another, less obvious hazard—carbon monoxide poisoning—has also sent many Sandy victims to hospitals. When people try to heat their homes and shelters with cooking stoves and kerosene space heaters, they sometimes improperly ventilate the area and allow poisonous exhaust to accumulate.

It’s easy to do. When you're huddled, shivering, next to a miserable kerosene heater in the middle of your frigid living room, or squatted in front of the open oven of your icy kitchen because it was the only heater you had, the very last thing you probably want to do is open a window. Still, you must.

Mountaineers, backpackers, and campers face exactly the same hazard if we use our stoves inside our tents, as we do sometimes when the weather gets colder. In fact, 30 deaths and 450 injuries occur annually in the U.S. due to people using stoves, grills and lanterns in their tents or vehicles while camping.

camp cooking

The best practice is to just toughen up and cook out in the snow. Use the stove only to cook, and use your sleeping bag and clothes to keep warm.

Recognizing Carbon Monoxide (CO) Exposure

Anything that burns fuel can create carbon monoxide, a gas you can neither see nor smell. As you breathe the exhaust—even exhaust diluted in plenty of fresh air (a combination similar to, say, secondhand smoke)—your red blood cells attach to CO more readily than they do to O2. The red blood cells also tend to hold onto CO longer; they don't let it go. As your blood's CO level rises, there's less and less room for the cells to carry any oxygen which, of course, you need in order to live. Too much CO equals not enough 02, and you can die.

The symptoms aren't flashy at all.  Headache, most commonly, plus fatigue, dizziness, nausea, maybe vomiting and diarrhea. Anyone who's ever climbed a 14,000-foot mountain has probably felt that way. Higher CO exposures will cause confusion, fainting, coma, seizures and death. A common scenario in fatal carbon monoxide poisonings is that the victim faints or just goes to sleep while the CO source continues to poison them, and they never wake up.


This winter camper is cooking the right way: outside. Photo by cruiznbye/Flickr.


Prevent this problem 100% of the time by never allowing yourself or others to breathe exhaust. If you suspect CO exposure, get the patient to fresh air immediately, and do not breathe any of the poison gas yourself. Anyone you suspect to have been exposed to CO should be brought to a hospital, as many complications are possible.

I hope this doesn't put you off of winter camping, which can be beautiful and lots of fun. You just need to be cautious and informed.

If you'd like to read about other winter health topics, see my blog posts about hypothermia and frostbite as well. Better yet, take a course from NOLS WMI, to learn about these and dozens of other wilderness medicine topics. Course information is available here.

Embedded photos, from top: tasty bread cooking outside, by peupleloup/Flickr; cooking gloves and mess, by Laurel Fan/Flickr.

Posted on at 8:15 AM

Tagged: NOLS WMI, Wilderness Medicine Institute, carbon monoxide, wilderness first aid and winter camping

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