Hydrogen is actually a combustible gas. But when you try to burn it, it explodes. However when you produce hydrogen in a laboratory, which is relatively less, and put a burning splint, it also explodes, but in a reduced form - a <span>POP </span><span>sound. The very small explosion (doesn't feel like one, does it?) extinguishes the flame.</span>
This would happen because the pressure on Mt.Everest is much more higher than the pressure at sea level, the can would probably be swollen so to this too.