Can you solve this?

Jack is placed in a cell with a dirt floor and only one window positioned so high no one could reach it. The cell is empty except for a shovel. It’s dry and hot in there, but Jack won’t get any food or drink anytime soon. He has only 2 days to break out of the jail. If not — he’ll die.

Digging a tunnel is not an option because it’ll take more than 2 days. How should Jack escape the cell?