How do you know? Have you tried every lighter you've owned above 5,000 Feet? Given that 14 out of 50 states in the US has at least one city over that, in fact many folks live over twice that high and some of those cities are above 50,000 full time residents. Hard to imagine what they do for lighters........OF
@OF Yes, I experienced it several times and other people confirmed the same. The first time I noticed it, was about 8 years back in a Swiss village called "Saas Almagell", it is exactly on 1600m and my lighter did not work properly anymore. When my friend did a bicycle tour and went over the Gotthard pass (2100m) he could not vape up there because the lighter did not work anymore. After descending a couple of hundred meters, the lighter worked again.
Funny, I read about this test with the hammer and the plane and I was wondering back then already, what type of burner that vape must have. I would like to understand a bit more about this and may order one of these special lighters just to see how it goes. Some years back I was on the look out for such a high altitude lighter, I think, "Colibri" got one of those. Interesting!
vapman