A rolling tool chest is really two problems in one: a top chest and a bottom rolling cabinet that are each heavy on their own, plus every drawer full of dense metal that adds up fast. Emptying the heaviest drawers first is what saves your back.
Pro tip: Photograph the layout inside each drawer before emptying it; foam organizer trays are painful to reassemble from memory.
Watch out: A fully loaded rolling tool chest can weigh 300 to 500 pounds; never try to lift one by hand, even with a partner, use a dolly and a ramp.