2 Sterno cans will boil the water. Cost effective.. NO.
But this is a pretty old topic (for those that didn’t look at the dates).
But all those that mentioned the floor jump boxs (electrical outlets) where right on. Also, the mall may do a drop line from the ceiling.. (encased in a nice looking conduit square box). Other thing you may want to look at are their rules for removing waste water, and bringing in fresh water to your setup. Kiosk space around here is outrages and requires a year long lease, if not more.. So renter be warned.