Temperature indicating device

A device for attachment to a bottle or the like which contains a liquid or other material, for purposes of indicating when the bottle is at a particular temperature most suitable for consumption of the contents of the bottle, said device comprising a thin support having an adhesive substance on a first surface thereof for attachment of said device to said bottle, and a temperature sensing element on the second surface, said temperature sensing element comprising a mixture of cholesteric crystals printed on said second surface, said mixture having a transition phase between the smectic and cholesteric phases of from 6.degree.-15.degree. C., said support further comprising colored areas adjacent to said sensing element, said colored area being of a succession of colors which successively correspond to the colors of the sensing element between 6.degree. and 150.degree. C., and wherein one of said colored areas is a marked area which identifies it as corresponding to the temperature which is most suitable for consumption, and a transparent layer covering at least said sensing element to insulate said sensing element from moisture, and wherein said transparent layer thermally insulates said sensing element from ambient temperature and has a thickness of between 150-600 microns, said device further comprising two arrows adjacent to said-colored areas on opposite sides of said marked area, each of said two arrows pointing towards said marked area in a manner so as to indicate to an observer whether the temperature being sensed by the device is too high or too low, and whether further cooling or heating is required.