It's the flooding problem most of all. I'm in one of the few Manhattan co-ops that still allows washing machines and dryers and it's a wonderful thing to have it in my apartment. But many landlords, co-op board and condos don't permit them because of the flooding.
Sodium acetate or hot ice is an amazing chemical you can prepare yourself from baking soda and vinegar. You can cool a solution of sodium acetate below its melting point and then cause the liquid to crystallize. The crystallization is an exothermic process, so the resulting ice is hot. Solidification occurs so quickly you can form sculptures as you pour the hot ice.
Of course, you need to know the best way to pack your cooler, and we are here to tell you how! To keep things cold with dry ice, you have two options. The first is to place the dry ice on the bottom of the cooler, cover it with a piece of cardboard with holes in it or a towel, and place your supplies on top.