Cold boxes for refrigeration are constructed by placing an inner liner inside a container and filling the space therebetween with insulation. The standard insulation now in use is plastic foam that is expanded in place. Naturally, a cold box must have an access opening which is closed by a hinged door. In the past, the method of attaching the periphery of the opening on the outer container to the periphery of the opening on the inner container was complicated and expensive. Also, in many applications, the opening was required to be covered with a breaker made, preferably, of plastic so that when heavy solid items such as a beer barrel, is knocked thereagainst, the cold box is not damaged to the point where the door would not seal effectively. In addition, since the outer container and inner liner are made of sheet metal, and if one attempts to place a sheet metal frame around the opening, this frame should be permanently welded or effectively sealed in place to prevent moisture from entering the space where the insulation is located. It is well known that moisture will deteriorate the insulation on freezing. One skilled in the art can visualize how difficult it would be to suitably weld or seal this metal frame around the opening without degrading the aesthetic effect of the cold box, and also do it economically.