Radiator under the counter

I have a hot water radiator that the previous owner thoughtfully
installed a countertop overtop of. The heat used to absorb into the
countertop and dissipate out through the exterior wall.

To remedy this, I've installed foil backed bubble wrap on the
underside of the counter. Now the hot air rolls right out into the
middle of the room where the counter top ends instead of being
absorbed into the wood.