My dad used to roast the weiners on our engine block. Wrapped in foil of course.
I think they were done in 5 mins. One day he almost exploded a can of beans he was heating. He also used to heat bricks to keep us warm on really cold nights...ah the old days.
Careful Pat, you're telling your age
I remember from my childhood (the smell of a greasy/oily Army tent) my mom wrapping a firebrick that was warmed in a campfire in a towel and placed in our (thin) sleeping bags for overnight warmth. She wouldn't use any rocks from the stream/river because they had a tendency to explode. Now, I realize this doesn't have anything to do with cooking... but it does give folks a different perspective of doing the same ole thing just a different way.