Oil line gelling from above ground tank to underground house connection. Furnace won't restart.

My furnace won't restart. I don't think the inside baseboards are frozen as I have some other less efficient heating. I think the outside oil line is gelling from the above ground tank. The line runs underground to the old house connection under the porch. I tried using a hairdryer outside but already tried the furnace button twice. Is there anything that can be done? Is there a company that can fix this in freezing temperatures? Currently have no hot water.