Having attended many baseball, basketball, and football games over the years, it always bothered me that the soda and beer vendors had to lug beer and soda up the many stairs of a sports park complex with tubs of ice and soda or beer. This had to hurt their backs by the end of the day, let alone doing this for days and days over months long summer or winter seasons.
Possible solution, combine a camper or military backpack with todays technology for cold packs and gravity. See Attached sketches.
The container can be changed to accommodate cans or bottles of various sizes. Refrigerated beer or soda can inserted from the top and retrieved from the bottom side of the container one at a time.
Recyclable cold packs keeps the already refrigerated cans cold saving production of ice. And by caring the load on ones back instead of out in front with ones hands also saves on potential work place injuries and OSHA issues.
It has already been proven that soldiers and campers can carry from 50 to 80 lbs. of gear on their back with minimum strain on their backs for hours.