Abstract: Food temperature vessel or other utensil comprising a thermochromic layer at a surface thereof indicating temperature of the food content of the vessel within a safe range above 60.degree. and below 70.degree. C. corresponding to achievement of safety conditions by raising the food content above the minimum temperature of the range to produce reversible protein denaturation in certain microorganisms to limit sporulation, and below a limit corresponding to irreversible protein denaturation and tissue injury of the tongue, lips or throat tissues of the user on the upper end of the range. The thermochromic layer goes through a transition from red to black across the range.