Slightly off topic, and I am unsure of how well they work at extreme altitude, but I always have a couple Walmart special road flares in the map pocket of my pack. I carry a bic too, but only use it when it is nice out and everything is hunky dory.

The hell with cotton balls dipped in vaseline, tree bark soaked in some other skank juice fuel and all that other gay ass jazz. When your fingers are numb and you're completely drenched, road flares straight up work and will give you a guaranteed 15 minutes of flame. Soaking wet wood gets lit up quickly too when you shove your flare in a pile of sticks like its a Thai hooker. I keep a couple in ziplock bags and make damn sure the cap is sealed well until it is time to start a bonfire in the pouring down rain.

[Linked Image]