they work fine at high altitude in the cold, you just have to keep them in an inside pocket.
In that case, they're not in the cold. Leave them in a cold pack, though, and it's another story. Then you need a Zippo.
As far as altitude goes, those butane bbq strikers usually fail somewhere around 5 to 6000'. The ones in our camper never work in the mtns and I've tried about every brand.
