Abstract: The invention relates to a device capable of indicating that at least one temperature threshold has been reached and/or exceeded, characterized in that the device includes a substrate (1), at least one of the surfaces of which comprises at least one externally visible visual and/or audio indicator (2), said substrate (1) including: at least one component (6?) capable of changing form and/or size when exposed to temperature, said changes that are carried out when said at least one temperature threshold is reached or exceeded causing the movement of said component (6?); at least one transmission or communication means (8) that enables the direct or indirect transmission of said movement of the component (6?) to and/or towards the visual and/or audio indicator (2), said transmission being expressed as: a change in the appearance of the indicator (2) if the latter is visual; and/or a release of an audio signal if the indicator (2) is an audio one.