I bought a sturdy camping lighter. It was the most reliable lighter I'd had, first time every time. Until I tried to use it at 14,000 feet. Nothing. Wouldn'

I bought a sturdy camping lighter. It was the most reliable lighter I'd had, first time every time. Until I tried to use it at 14,000 feet. Nothing. Wouldn't work at all. Luckily I had a cheap, disposable lighter as backup. It worked fine above 20,000 feet.