Leweee, one of my employees used to use the engine in his van to heat his lunch, those zip-top cans of stew and such. Had the dog-house set so he could just tilt it back, stick the can under the air cleaner, and toss the cover back closed, and after a few minutes at idle had it just right.
Then one fateful day his pager went off, right after he stuck the can in there. He raced off, forgot all about lunch, that is until about 1/2 an hour down the highway, and his apprentice asked about the smoke coming in around the engine cover.

Apparently it took months for the smell to completely clear.
