Could hugelkultur be adapted for light underfloor heating?

Since decaying wood gives off small amounts of heat, I was thinking that if done properly, stacking rotten logs in some kind of cavity under a relatively thin floor might at least keep the temperature above a certain level. You'd appreciate that in a cold climate if you could manage it. Any feasibility? Or am I way off?

I think for the work, it'd make more sense to haul around undecayed wood to burn in a wood heater. I imagine an underfloor compost arrangement would give off more heat, and here you could possibly toss kitchen scraps or other household wastes (shit, etc.). The difficulty would be access, both for input and then clearing out later. I'd hate to crawl under my house and scoop out decayed matter.

Another consideration that comes to mind is moisture. Floors tend to have vapor barriers below them (at least in my humid/wet climate) to prevent rot. They're also often insulated (to prevent heat loss). These would make for other other obstacles to using such a system in a conventional house. But if you're doing something unconventional/natural perhaps you could find biological processes to add heat to your house.

I'll pass on a giant heap of mold & bacteria under my house.  But I would consider placing a compost or hugelculture against an exterior wall, a sort of living berm, if you will. 

Hugelculture can't be giving off that much heat anyway, if plants are living in it, at least compared with a compost @ 60c/140f...