A cooler or freezer box is built from insulated panels. Behind a store, that box can stand inside a steel frame of columns and beams. The frame carries what the drawings put on it, such as a roof or the equipment. So the drawings, not the box, decide how heavy the steel is.
It goes up like any other steel frame, only smaller. Columns first, stood on their anchor rods and anchored. Only then do the beams connect them, because a loose column can't take a beam. Once the frame is plumbed and bolted, the welds go in where the drawings call for them.
The OSHA steel erection standard sets how columns are anchored and how beams are secured before the hoist lets go. Those rules don't shrink with the frame. A column doesn't care how big the building is, so we follow them here too. The full sequence, step by step, is on the Beam and Column Installation page.
A freezer box usually sits in the same kind of frame, put up in the same order. If its drawings differ, we set what they show.
We stand the columns and weld the connections ourselves. That way the frame doesn't sit between two trades before it's ready for the box.