Abstract: A structural component for forming sleeping bags or insulated items of wearing apparel is formed of an outer layer of waterproof or the like material and a laterally spaced inner lining material. Attached to the inner surface of the outer material is a layer of heat insulating material such as cotton, the upper surface of which is laterally spaced from the inner surface of the lining material. Extending transversely between the upper surface of the cotton material and the inner surface of the lining material are a plurality of spaced partition sheets forming tubular cavities therebetween. These cavities are filled with feathers and sealed at their outer ends.