A heat shield (40) is disclosed having a first layer (42) with a reflective surface, a second, heat fusible layer (44), a third insulating and reinforcing layer (46), and a fourth layer formed of pressure sensitive adhesive (48). The edges of the layers align with one another to form a common perimeter to which heat and pressure are applied to fuse the heat fusible layer to the other layers and bond the layers to one another. The heat fusible layer forms a seal on the perimeter that prevents the diffusion of fluids between the layers.