Patent ID: 7784301

Claim:
A method of delivering frozen products comprising: storing frozen products in a cold-insulating container; the cold-insulating container comprising: a collapsible cold-insulating container comprising four peripheral walls, a bottom face, and a flexible rectangle bottom face sheet, the container being collapsible with the four peripheral walls, the bottom face, and the bottom face sheet remaining connected with each other, wherein the four peripheral walls are connected into a square shape so as to be foldable relative to one another, the bottom face is connected to the peripheral walls along a lower side edge of at least one of the peripheral walls, the bottom face being rotatable around the lower side edge toward an inside of the container, the bottom face is formed enveloping a vacuum heat-insulating material therein, two of the peripheral walls on opposing sides of the container each have a folding line extending from an upper side edge to a lower side edge thereof, each folding line being located at a middle of the respective peripheral wall, each of the peripheral walls having the folding line also including two vacuum heat insulators, the insulators being separated along the folding line, respective halves of the peripheral wall on each side of the folding line being rotatable around the folding line such that the folding line moves toward the inside of the container, the bottom face sheet is attached to the four peripheral walls along lower side edges of the walls, so as to cover an entire outer surface of the bottom face, when the bottom face is rotated into a close position to form the box, and the container has a collapsed state, in which the bottom face is rotated inward around the lower side edge and positioned approximately parallel with and between two opposing peripheral walls not having the folding lines, and the halves of the two of the peripheral walls having the folding lines are rotated around the folding lines such that the two peripheral walls are folded approximately in half, with each half positioned approximately parallel with and between the two opposing peripheral walls not having the folding lines; and loading the cold-insulating container in a vehicle that is maintained at a temperature higher than a freezing temperature of the frozen products.