The present invention is generally in the field of measuring and indicating techniques and relates to a time-temperature indicating device and methods of manufacturing and reading this device. More specifically, the time-temperature indicator (TTI) device comprises at least one active reactant being at least a part of a component that is configured to be either an electrical component or transformable into an electrical component, said at least one active reactant being selected to be affectable by a chemical and/or physical reaction effecting a change in at least an electrical property of said electrical component at a rate that is time-temperature dependent.