A thermally insulated shipping container comprising: an inner structure including an inner base, a front inner wall, a rear inner wall opposed to the front inner wall, a pair of opposed side inner walls each extending between the front and rear inner walls and an inner lid; an outer structure including an outer base, a front outer wall, a rear outer wall opposed to the front inner wall, two side outer walls each extending between the front and rear outer walls and an outer lid; and a cavity between the inner and outer structure arranged to receive a plurality of cool packs; wherein the container, when empty, is arranged to be transported disassembled in a flat packed state prior to being assembled for use, characterised in that when disassembled, each side outer wall comprises a first portion and a second portion separate to the first portion, which first and second portions are arranged to abut together to form the respective side outer walls when the container is assembled for use, and in that the respective first portions of both of the two side outer walls are joined substantially at right angles to respective ends of the front outer wall to form a U-shaped outer wall section, wherein the inner lid, rear inner wall, front inner wall and side inner walls are arranged so that they can be stacked flat upon the inner base, wherein the lengths of two first portions of the outer side walls are sufficient that when the inner base is on the outer base and the remaining components of the inner structure are stacked flat upon the inner base, the U-shaped outer wall section may be placed inverted on the outer base such that it bridges over the components of the inner structure. an inner structure including an inner base, a front inner wall, a rear inner wall opposed to the front inner wall, a pair of opposed side inner walls each extending between the front and rear inner walls and an inner lid; an outer structure including an outer base, a front outer wall, a rear outer wall opposed to the front inner wall, two side outer walls each extending between the front and rear outer walls and an outer lid; and a cavity between the inner and outer structure arranged to receive a plurality of cool packs; wherein the container, when empty, is arranged to be transported disassembled in a flat packed state prior to being assembled for use, characterised in that when disassembled, each side outer wall comprises a first portion and a second portion separate to the first portion, which first and second portions are arranged to abut together to form the respective side outer walls when the container is assembled for use, and in that the respective first portions of both of the two side outer walls are joined substantially at right angles to respective ends of the front outer wall to form a U-shaped outer wall section, wherein the inner lid, rear inner wall, front inner wall and side inner walls are arranged so that they can be stacked flat upon the inner base, wherein the lengths of two first portions of the outer side walls are sufficient that when the inner base is on the outer base and the remaining components of the inner structure are stacked flat upon the inner base, the U-shaped outer wall section may be placed inverted on the outer base such that it bridges over the components of the inner structure.