Device (100; 110; 120) for temperature monitoring of a cryopreserved biological sample, comprising a) a sample container (1; 41) with a receiving space for receiving a biological sample, in particular a cryogenic tube; and b) at least one chamber (102; 112; 122), the inner space of which is not fluidically connected to the receiving space and is only partially filled with an indicator substance, the melting temperature of which lies in a range from -20°C to -140°C, wherein the chamber has a barrier (54; 54b; 54c; 103; 113; 123) which brings about that, if indicator substance is located in a first sub-region (52a; 102a) of the chamber in the liquid state, this indicator substance passes into a second sub-region (52b; 102b) of the chamber in a delayed manner, wherein the device is configured so variant i): that the indicator substance is stored in a receptacle (105; 115) which tightly encloses the indicator substance in the liquid state; and the device has an activation part (104; 114; 124) which is guided movably in relation to the receptacle (105; 115) and which can be moved from a starting position into an the activation position, wherein the movement into the activation position brings about that the activation part (104; 114; 124), as a result of mechanical pressure, destroys the receptacle (105; 115) at at least one point in particular in such a manner that the receptacle becomes permeable for the indicator substance in the liquid state; or variant ii): that the barrier is a separating element (54; 54b; 54c) which is permeable in relation to the indicator substance in the liquid state and which is arranged between the first sub-region and second sub-region; wherein the separating element is configured, in the case of cooling of the device to a storage temperature which lies below the melting temperature of the indicator substance, to tear at at least one point (55a; 56a; 57a) as a result of thermal contraction so that the indicator substance can pass in the liquid state via the opening (55b; 56b; 57b) formed by the at least one tear point from the first sub-region into the second sub-region. a) a sample container (1; 41) with a receiving space for receiving a biological sample, in particular a cryogenic tube; and b) at least one chamber (102; 112; 122), the inner space of which is not fluidically connected to the receiving space and is only partially filled with an indicator substance, the melting temperature of which lies in a range from -20°C to -140°C, wherein the chamber has a barrier (54; 54b; 54c; 103; 113; 123) which brings about that, if indicator substance is located in a first sub-region (52a; 102a) of the chamber in the liquid state, this indicator substance passes into a second sub-region (52b; 102b) of the chamber in a delayed manner, wherein the device is configured so variant i): that the indicator substance is stored in a receptacle (105; 115) which tightly encloses the indicator substance in the liquid state; and the device has an activation part (104; 114; 124) which is guided movably in relation to the receptacle (105; 115) and which can be moved from a starting position into an the activation position, wherein the movement into the activation position brings about that the activation part (104; 114; 124), as a result of mechanical pressure, destroys the receptacle (105; 115) at at least one point in particular in such a manner that the receptacle becomes permeable for the indicator substance in the liquid state; or variant ii): that the barrier is a separating element (54; 54b; 54c) which is permeable in relation to the indicator substance in the liquid state and which is arranged between the first sub-region and second sub-region; wherein the separating element is configured, in the case of cooling of the device to a storage temperature which lies below the melting temperature of the indicator substance, to tear at at least one point (55a; 56a; 57a) as a result of thermal contraction so that the indicator substance can pass in the liquid state via the opening (55b; 56b; 57b) formed by the at least one tear point from the first sub-region into the second sub-region. variant i): that the indicator substance is stored in a receptacle (105; 115) which tightly encloses the indicator substance in the liquid state; and the device has an activation part (104; 114; 124) which is guided movably in relation to the receptacle (105; 115) and which can be moved from a starting position into an the activation position, wherein the movement into the activation position brings about that the activation part (104; 114; 124), as a result of mechanical pressure, destroys the receptacle (105; 115) at at least one point in particular in such a manner that the receptacle becomes permeable for the indicator substance in the liquid state; or variant ii): that the barrier is a separating element (54; 54b; 54c) which is permeable in relation to the indicator substance in the liquid state and which is arranged between the first sub-region and second sub-region; wherein the separating element is configured, in the case of cooling of the device to a storage temperature which lies below the melting temperature of the indicator substance, to tear at at least one point (55a; 56a; 57a) as a result of thermal contraction so that the indicator substance can pass in the liquid state via the opening (55b; 56b; 57b) formed by the at least one tear point from the first sub-region into the second sub-region.