Cleaning out my shed just now, I ran across a pack of emergency candles, big fat suckers that together offer 100 hours of burn time - for light, heat, etc. - complete with the statement 'These candles could save your life!"

OTOH, I suppose there is the possibility, faint tho it be, that they might not save your life....

You would think they would offer a lifetime guarantee if they are any good at all.