PREVENTING ASPHYXIATION WHILST CLIMBING

DON’T THINK IT CAN’T HAPPEN. WE HAVE EXPERIENCED THE EFFECTS OURSELVES AND WITNESSED AT LEAST ONE FATALITY BECAUSE OF IT. ASPHYXIATION FROM TOXIC GASES AND LACK OF AIR IS A REAL HAZARD WITH EXPEDITION CLIMBING

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SERIOUS CLIMBING MEANS COOKING INSIDE A TENT OR SNOW HOLE BECAUSE IT IS NOT REALISTIC OUT IN THE OPEN WHEN THINGS ARE COLD, WINDY, AND STEEP. THIS MEANS SWAPPING ONE SET OF RISKS FOR ANOTHER, WHICH THEN MEANS ANOTHER ARRAY OF THINGS TO UNDERSTAND AND GET RIGHT.

IT IS ONE THING TO COURT MORTALITY WITH THE INHERENT DANGERS OF CLIMBING SUCH AS ROCK FALL, ALTITUDE AND GEAR FAILURE. IT IS ANOTHER TO TEMPT THINGS WITH BASIC HOUSE KEEPING.

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ASPHYXIATION COMES IN 2 WAYS; TOXIC GAS AND LACK OF AIR. BOTH ARE BECAUSE WHAT YOU ARE BREATHING HAS BEEN CORRUPTED WITH OTHER GASES THAT EITHER POISON YOU OR BLOCK OXYGEN UPTAKE, AND BOTH AS SYSTEMIC HAZARDS THE RESULT OF BAD PRACTICE, WITH SYSTEMIC SOLUTIONS.

THE AIM IS TO MAKE PREVENTION STANDARD AS PART OF YOUR TECHNIQUE, BECAUSE IN SOME CASES MITIGATION ISN’T MAYBE POSSIBLE WITH FATAL CONSEQUENCES. GET IT RIGHT AND YOU CAN COOK SAFELY INSIDE A TENT. GET IT WRONG AND YOU SUSTAIN A SERIOUS RISK IN WHAT ALREADY IS A PRETTY RISKY GAME.

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CARBON DIOXIDE

CO2 ASPHYXIATIONIS USUALLY THE RESULT OF THE BUILD UP FROM RESPIRATION AND/OR OXYGEN BEING CONSUMED BY A STOVE, AND CAN HAPPEN EVEN WHEN NO STOVE IS BEING USED. IT DISPLACES THE AIR MIX YOU SHOULD BE BREATHING WITH SOMETHING YOU CAN’T USE. CO2 IS HEAVIER THAN AIR, BUT HAS A SLIGHT FAIL SAFE, WHERE YOU CAN FEEL IT BUILDING AS BREATHING GETS MORE DIFFICULT. FROM EXPERIENCE, IT CAN WAKE YOU UP. MOSTLY…

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CARBON MONIXIDE

CO IS A POISON, USUALLY FROM INCOMPLETE COMBUSTION. IT IS ALMOST THE SAME MASS AS AIR, SO IT DOESN’T REALLY SINK. UNLIKE CO2 IT ISN’T NOTICED BY YOUR BREATHING, INSTEAD IT FEELS LIKE DROWSINESS, WHICH IS IT’S DEADLY NATURE. FROM EXPERIENCE CO CAN CREEP UP UNANNOUNCED AND KILL WITHOUT A STRUGGLE. CLIMBERS HAVE DIED WHILST EATING.

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OTHER FUMES

LEECHING PROPANE AND BUTANE, SPILLED FUEL, PLASTICS, RUBBER, PAINT AND COATINGS, BURNT FOOD AND OVERHEATED METALS ALL RELEASE FUMES, NONE OF WHICH ARE GOOD FOR YOU AND ALL OF WHICH CORRUPT THE AIR MIX IN AN ILL-VENTILATED SPACE. GLOVES AND JACKETS ACCIDENTLY TOUCH FLAMES, POTS CAN BOIL DRY, LAMINATES CAN MELT, STUFF CAN GET STUCK TO THE BOTTOM OF COOKING POTS. THESE FUMES CAN RANGE IN EFFECT FROM IRRITATING TO EXTREMELY TOXIC LONGTERM.

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BE AWARE THAT ALL THESE HAZARDS CAN BE SIMULTANEOUSLY PRESENT.

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THINK OF YOUR AIR SPACE AS A BLOCK OF AIR YOUR HAVE TAMED IN A WILDERNESS, THAT NEEDS AN INPUT AND OUTPUT IN ORDER TO STAY HEALTHY. BY NATURE OF IT BEING MORE STILL THAT WHAT’S OUTSIDE BECAUSE OF REDUCED CONVECTION AND THE HEAT FROM YOUR PRESENCE, HOWEVER MINIMAL THAT IS, MEANS THAT BLOCK OF AIR IS LAYERS OF CONSTANTLY RISING VAPOR THAT NEEDS INPUT FROM BELOW AND OUTPUT ABOVE. OUTSIDE, BECAUSE IT IS MOVING MORE, HAS LESS PRESSURE THAN INSIDE, SO DRAWS THAT BLOCK OF AIR OUT WHERE YOU LET IT.

OF COURSE YOU ARE PROBABLY TRYING TO RETAIN MUCH OF THAT HEAT WHILST LETTING THE BAD STUFF BE SUCKED OUT THE TOP AND THE BOTTOM, AND THE KEYS HERE ARE TO INSULATE THE FLOOR, PITCH THE TENT TAUGHT (AND DYNEEMA HELPS) SO IT DOESN’T BILLOW MUCH, AND KEEP COLD STUFF LIKE METAL AND ICE OUTSIDE SO IT DOESN’T ABSORD YOUR PRECIOUS HEAT.

AVOIDING PROBLEMS FROM ASPHYXIATION IS MATTER OF METHOD AND AWARENESS, OF USING ALL YOUR SYSTEMS WELL AND KNOWING THE SIGNS.

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BE VIGILANT

IN THE TENT, NEVER JUST JUMP IN, GET THE STOVE ON THEN CRASH OUT. SO LONG AS THAT STOVE IS BURNING YOU NEED ALL EYES ON IT TO MONITOR ACCIDENTS WITH MELTING GEAR AND THE EFFECTS OF CO POISONING. THIS MEANS SWITICHING YOUR BRAIN FROM THE VIGILANCE OF THE CLIMBING TO THE VIGILANCE OF THE BIVY, AND RECUPERATING WITH ONE EYE OPEN.

WATCHTHE TEMPERATURE AND WATCH YOUR PERCEPTION, BECAUSE BECOMING CLUMSY AND DOPEY IS A GOOD SIGN OF CO POISONING. IT FEELS DIFFERENT TO EXHAUSTION, BEING COMFORTABLE AND WITH A VERY LOW ENERGY LEVEL, DIFFERENT TO THE INNERVATED AND EDGY FEELING OF A HARD DAY CLIMBING. IF YOU FEEL THIS, VENT IMMEDIATELY, BUT DON’T TURN OFF THE STOVE. YOU NEED THE TEMPERATURE DIFFERENTIAL TO PUSH CLEAN AIR THROUGH. STICKING YOUR FACE OUTSIDE HELPS WITH URGENCY, BUT DOESN’T FIX THE PROBLEM INSIDE, SO ONCE YOUR HEAD CLEARS COME BACK IN AND GET THE FLOW OF AIR FROM LOW TO HIGH ZOOMING.

KEEP SNOW BASHED OFF THE WALLS AND VENTS AND HAVE THE OCCASIONAL LOOK OUTSIDE, AND EITHER SIDE OF COOKING ALLOW YOURSELF A FEW MINUTES OF CAREFULLY BLASTED RAW HEAT TO KEEP THE ENVIRONMENT STABLE.

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USE A HANGING STOVE

HANGING STOVE MOVE THE LAYER OF WARM AIR HIGHER, SO A COLD SINK CAN SIT BELOW IT WHERE CO ACCUMULATES AND CAN BE DRAINED AWAY THROUGH A VENT. YES, THIS SUCKS A BIT FOR WARMING YOUR TENT RIGHT THROUGH – THOUGH THE LOWER LAYER YOU ARE IN YOUR SLEEPING BAG – BUT IT ALLOWS LOWER VENTS TO OPERATE WELL UNASSISTED. ESPECIALLY IF SNOW IS BUILT UP AROUND THE BOTTOM OF YOU TENT, OVER THE BOTTOM OF THE DOOR ZIPS, YOU NEED THIS COLD/CO TRAP A BIT HIGHER.

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VENT LOW

FEW TENTS THESE DAYS HAVE DEDICATED LOW VENTS, THE EXPECTATION BEING YOU WILL UNZIP THE BOTTOM OF THE DOORS, BUT STILL FEW HAVE THE RIGHT SORT OF ZIPS OR ENOUGH DOORS TO DO THIS WELL. A SINGLE VENT OF A FEW CMS IS NOT REALLY ENOUGH, AND SHOULD BE JAMMED OPEN WITH SOMETHING LIKE A PISS BOTTLE SO YOU CAN TANGIBLY FEEL THE EXCHANGE. SLEEP WITH THIS.

GOOD LOW VENTS MEAN YOU CAN DRAIN DEAD AIR OUT INTO THE WIND AND ALLOW FRESH AIR IN TO BE HEATED AND FLUSHED THROUGH. IF YOUR TENT FLOOR IS SEALED OFF FROM CONDUCTION WITH INSULATING MATS AND GEAR, THIS AIR NEED NOT BE TOO ICY OR EVEN COLD ENOUGH TO CONDENSE MUCH.

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ONLY USE TENTS WITH HIGH VENTS

TENTS WITHOUT VENTS AT THE HIGHEST POINT SHOULD NOT BE PART OF HIGH CAMPS – AND IT’S SURPRISING HOW MANY ARE LIKE THIS, INCLUDING FROM THE MAIN BRANDS. YOU NEED TO RELEASE STEAM AND CREATE A THROUGH DRAFT JUST LIKE A CHIMNEY, AND THE LAST THING YOU WANT IS A LAYER OF DEAD AIR SOAKED IN CO FORMING THAT WILL COOL AND DESCEND WHEN THE STOVE IS TURNED OFF.

VENTING AT THE TOP OF THE DOOR ZIP USUALLY DOESN’T WORK AS IT THEN MEANS THE STANDARD DOUBLE-SLIDER ZIP CAN’T BE USED TO VENT DOWN LOW. THE BEST TENTS HAVE A CENTRAL HIGH POINT WHERE POLES CROSS, THAT IS BOTH STRONG UNDER SNOW, HOLDS THE STOVE, AND IS SURROUNDED BY VENTS SO A CROSS CURRENT CAN BE FORMED

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USE TENTS WITH STEEP WALLS

STEEP WALLS MAKE IT EASIER KEEPING SNOW OFF THE SIDES OF YOUR TENT, WHICH IS WHERE YOUR VENTS NEED TO BE LOCATED AND ALSO WHERE YOU WANT ACCESS TO THE LOWER PRESSURE OUTSIDE.

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KEEP THE AMBIENT HEAT UP

OCCASIONALLY BLAST JUST STRAIGHT HEAT FROM THE STOVE AS THIS KEEPS YOUR BLOCK OF AIR PUSHING UPWARDS AND MAKES THE CANISTER WORK BETTER. NOTHING MAKES A CANISTER MORE EFFICIENT THAN WARMING THE ENVIRONMENT, ie INCREASING AMBIENT PRESSURE, SO THE FUEL IGNITES BETTER RATHER THAN IN PART LIQUID FORM.

IF YOUR STOVE HAS A WINDSCREEN OR FLAME GUARD, SUCH AS JETBOILS, EITHER REMOVE IT OR OCCASIONALLY LIFT THE POT SO HEAT CAN FLOOD OUT INTO THE TENT.

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ALLOW SOME VAPOR

NOTHING INCREASES A PRESSURE INCREASE INSIDE YOUR BLOCK OF AIR THAN A BURST OF VAPOR FROM BOILING. EVEN THOUGH TOO MUCH FREEZES AS ANNOYING FROST, A LITTLE BIT RAMPS UP THE TEMPERATURE JUST LIKE A SAUNA AND PUSHES A LOT OF AIR THROUGH. FOLLOWED BY A BAST OF DRY HEAT IT WON’T STICK AROUND TO FREEZE

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USE A FLUX RING POT

FLUX RINGS CAPTURE MORE VAPOR TO BURN AND REDUCE BOTH ESCAPING PROPANE/BUTANE AND CARBON MONOXIDE. THEY ARE ALSO THEREFORE MORE EFFICIENT, GETTING MORE FROM THE CANISTER YOU CARRY. LARGER FLUX RINGS CAPTURE AND IGNITE MORE GAS WHICH MATTERS AS THINGS GET COLDER AND HIGHER.

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USE A GOOD STOVE

READ THE DATA AND RESEARCH WHAT STOVE YOU USE BECAUSE SOME ARE NOTORIOUS FOR THE CO THEY RELEASE. STOVES WITHOUT PREHEATING TUBES WILL ALWAYS BE MORE PRONE TO CO EMISSIONS BECAUSE THE FUEL RELEASES AS LIQUID WHEN THE PRESSURE IS LOW, BUT EVEN STOVES WITH THE TUBE NEED A BIT OF TIME BEFORE THINGS START WORKING AT THEIR BEST. TUBES THAT ARE MORE EXPOSED TO THE FLAME OBVIOUSLY HEAT FASTER.

STOVES WITH REMOTE CANISTERS SUCHAS THE BLADE 2 AND ULTRA SPIDER ARE FAR EASIER TO KEEP WARM THAN ON-TOP STOVES, BUT THE ABILITY TO INVERT AND LIDUID FEED NEEDS TO BE UNDERSTOOD WITH THE RISKS. IT IS FAR BETTER TO OCCASIONALLY INVERT WHILST THE AMBIENT TEMPS ARE STILL WARM, OR TO QUICKLY WAVE OVER THE FLAME IF THINGS HAVE STARTED TO SLOW DOWN. WATCH AND LISTEN TO THE FLAME, FOR A HEALTHY COLOUR AND SOUND. IT SHOULD BURN BRIGHT BLUE WITH A HUM AND IF NOT THE PRESSURE IS LOW, WITH A YELLOW FLAME MEANING IT IS BURNING MOSTLY BUTANE WITH THE PROPANE LEECHING OUT TOO LIQUID TO IGNITE.

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IF COOKING IN A TENT IS NORMAL FOR YOU, AS IT IS ON EVERY STEEP ROUTE, THE THESE ARE PRACTICES EVERY BIT AS RELATED TO YOUR SAFETY AS ANYTHING YOU DO ON ROPE. ONCE WORKED OUT AND UNDERSTOOD, YOU PILOT YOUR COOKING AND TENT SPACE INTUITIVELY BUT NEVER BY CHANCE.