I never have fed out of the enclosures. Mine all get fed in the tubs and I have no issues with feeding responses. I dont think that it will hurt the snakes on a warm floor, but to me it is just more un-needed work to do when feeding. I would check the floor with a temp gun tho. Concrete has a way of pulling the cold out of the ground, no matter what climate you are in. When I lived in Hawaii my floors were what I would have considered too cold for a reptile, but if you are good then you are good.