So the mini fridge is plugged in? If so the condenser will burn out if it's open all the time, you would be better off and cheaper to just buying an AC unit for the room to provide a cool place for the chin. There really is no replacement for an AC for more then a couple hours, if you can't do a window unit were you live there are portable AC units you can buy. The only cooling tricks are for temporary fixes until you can get the temp back down into the safe range (70F or below). Ideally you want to keep the room around 68F that way if the AC goes out you have time to figure something out or buy a new AC before the temp gets too high. Tiles are really only good for additional cooling in an already cool room, like after the chin has been running around, and only "work" if the chin sits on them. Short term when it's hot you can change out tiles every half hour or so with ones from the fridge or freezer, as well as wrap water bottle in fleece and freeze them, changing them out for frozen ones as they melt. You would need to do that until the room is back down to 70F or below.