Paul M. Eldridge wrote:
Is there any insulation underneath the slab and, if so, how much?
Carpet and under pad are reasonably good insulators and so more of
this heat will be re-directed downward and out of your home. It
doesn't strike me as a good idea, especially if the slab is
uninsulated.

Yes, the slab should be insulated from the ground no matter what floor
covering is selected.

Matt