Made my usual coffee in the office today; mug of water in the microwave for 2:34, and a couple of tablespoons of Alternative Grounds sustainable, organic Costa Rican waiting in the Mug Mate. I didn’t think much of the fact that I had about 2/3 of my usual liquid level in the mug, and threw the filter in anyway.
A couple of seconds of extreme frothing over later, I realised this was not so smart. I’d superheated the water, and the grounds and mesh of the filter were providing excellent bubble nucleation sites. Apart from having to mop up very weak coffee from a very wide area, no harm was done. I certainly didn’t come anywhere near burning myself.
Snopes’s article on the microwave boilover urban legend is pretty good, despite the noxious popups.