A thermally insulative device and an associated method of using the device for use in temporarily enshrouding a box are disclosed. The device includes the interconnected elements of a one-piece composite jacket, a plurality of primary coupling strips, a plurality of complementary coupling strips, a plurality of straps, and a buckle. The jacket includes a plurality of panels integrally formed together with a plurality of flaps. The method includes the steps of buckling, carrying, contacting, disconnecting, folding, getting, laying, lifting, lowering, obtaining, placing, tying, unbuckling, unwrapping, and wrapping.