A method of ensuring that meat has been adequately cooked to doneness, wherein a substrate, such as a foil, film, fabric, laminate, label, card, or paper, having a thermo-sensitive color-forming coating thereon, is placed onto meat pieces such that cooking causes the coating to change color at a predetermined temperate. Said color-forming coating is comprised of ingredients generally recognized as safe as food additives or as food colorants by the United States Food and Drug Administration (FDA), or as materials FDA-approved for food contact. A further embodiment of this invention relates to labels that visibly change color, or produce a visible image or code, which may be used to determine if a product has been exposed to a given temperature.
