If heat is what results from the fission of atoms in nuclear reactors and/or RTD generators, then a rapid heating and expansion of material to gas would create something not unlike an explosion, no?
Unless you are telling me that nuclear reactors and thermal decay modules are not real, as well.
Since I can make a neutron source from a dense plasma focus device (nuclear fusion - these are already able to operate well in excess of the zero point)… and we can confirm it makes heat - why would I suppose that the Megumin version of that phenomenon is impossible?