My personal best effort - I had just purchased a new cigarette lighter, but it didn't seem to be working. It was one of those ones without a wheel - the safety was that you had to push in the latch to depress the spark.
Someone suggested I hold it up to my ear to hear if the gas was flowing. So I held it up to my ear, and sparked it, where it promptly set fire to my hair. Not in a serious manner, but still...
Now, I don't know if I missed the "let it cool a while first" instruction, but boiling hot stock + very cold bowl = booom!
This is very similar to something stupid I did. Mine was a collective of stupid. Myself, DH and 2 friends (ALL SOBER) were making mulled wine on the stove top. Its finished, and we're getting ready to serve, and I toguht "wouldn't this be prettier if it was in a jug, and not a saucepan?" So I grabbed a glass jug (and wedding gift) and poured the boiling hot liquid into it.
THe very thick base of the base blew off. Thank goodness it was in the sink so we didn't all getcovered with glass and hot liquid!
I still can't fathom how not one of us didn't twig that it was a bad idead.
I was trying to boil sugar once, but my candy thermometer said it wasn't getting hot and it wasn't boiling at that point so I brilliantly stuck my finger into the pot to see if it was hot. It was. I ended up sleeping with a piece of Aloe on my finger.
I think we've all done that "Is this thing hot?" *touch* YES!