Fervence
Any level of heat, that is beyond the level of scientific measurents. A source of heat, so hot, that theres no way to scientificaly determine an "Actual" temperature.
An example of "Ferveric heat" would be the plasma balls and gases "Inside" of the sun, though the outside surface of the sun, usually is where the gases spread out, it's the coe of the sun, where the heat itself combusts, where "Ferveric tempratures" are said to exist.