I was on the rooftop of a frozen pizza factory the made Taylor Street brand and public school pizzas in Elk Grove. At such low temperatures, the refrigerant (R-502) gets the oil in a holding freezer's refrigeration system a little funky, causing the system to shut down on the low pressure control. My job was to climb up on the roof, walk to the other end of the building, take off the cover and hit the control's reset then pray it stayed on.
The night Mayor Daley #1 died... On a roof, while my dad tried to get a new fangled electric ignitor operational again.
Good Times...
Thus the reason I didn't follow in my dad's footsteps.