excerpt:
…
Not only would it be unsafe, the USGS said, but the marshmallows would simply taste bad. The vent could be releasing sulfur dioxide or hydrogen sulfide — which both emit not-so-pleasant smells — and the sulfuric acid from vog, or volcanic smog, could create a “pretty spectacular reaction,” the USGS said.
…
When I was in my early teens, I went on a school trip to Italy. It included a visit to Pompeii and Vesuvius. The guide at the latter had a good trick of frying eggs on hot stones, near to where there was still bubbling lava.
“would simply taste bad”
This is hilarious. I showed it to a couple friends. 
I’d think the lava might be a bit warm but then again I’m entering yet another Texas summer which may or not be hotter than the lava.
That would pretty much guarantee a “Darwin Award”, although Andreas Viestad cooked steak on a hot rock next to a crevice in some hot spring or volcano, on New Scandinavian Cooking. Seems like this technique is as far from “new” cooking as it is possible to get!
