LOL. "Heat" is the precursor to pretty much every source of energy man uses.
Oft times heat is the waste or by product or work already done....eg after a quantized level relaxes back to a transitional or ground state you almost always get heat....occassionally you get light-—light being the end goal not the heat.
that is just one example... and you can laugh all you want but accomplishing cold fusion is not going to happen so keep chasing