An insulating paperboard contains at least one layer of cellulose fibers. The one layer is at least partially composed of bulky fibers. The paperboard is sufficiently insulated to provide a hot water .DELTA.T across the paperboard of at least 0.7.degree. C..+-.2.3.degree. C. per 0.1 mm of caliper. The paperboard may be embossed to decrease surface transmission of heat. A hot cup may be produced from the insulating paperboard.