I had a butane lighter explode in my shirt pocket one day as I was driving at about 75 on the highway.
No fire or anything, just a loud pop and my shirt sort of billowed out, and I felt the sting of the plastic shards hitting me(no penetration of the flesh though).
I instinctively put my hand over the spot, and feeling the dampness on my shirt and the sting, I thought I'd been shot.
I pulled to the side of the road to bleed to death without endangering others (but I STILL got a 48.sump'n on the bastard test) and discovered what had happened.
I think the sun's rays through the windshield overheated the butane and caused the pressure to exceed the manufacturers intended maximum.
This was pre-sniper being several years ago, but my first thought was that I'd been shot.
It's nice to know I don't over-react, as no severe panic reaction happened, but the adrenalin was a nice rush.