A friend and I recently took a trip to the mountains (9100 ft elev) with our Vapcaps. We made sure our lighters were filled and took a couple of extras just in case. When we got up there, none of them worked, and we had to go to town and purchase a couple. The lighters worked perfectly in the higher elevations, and then back at home. I find it hard to believe there are "special" lighters that work at high altitudes. Would ours have worked it we had filled them at the higher altitude instead of before we left?