Thermal trigger device for triggering an automatic closure of a fire damper in an air channel, wherein the thermal trigger device is embodied for attachment to the air channel and can be connected to an actuator, via a connecting cable comprising at least one first and second line (M,VS), for closing the fire damper if a predeterminable channel air temperature limit value (θ Gi) inside the air channel is exceeded, - wherein the thermal trigger device has an electronic control unit and a first temperature sensor connected to the control unit for continuously detecting a channel air temperature value (θ i) inside the air channel, - wherein the control unit has a first serial data interface or wherein the thermal trigger device has a first serial data interface connected to the control unit, - wherein the first serial data interface can be connected to an interface line as a third line of the connecting cable, - wherein the control unit is set up to output a trigger signal at the first serial data interface if the channel air temperature limit value (θ Gi) is exceeded by the channel air temperature value (θ i) or to stop the output of a non-trigger signal (BEAT) at the first serial data interface, - wherein the control unit is connected to a second temperature sensor for continuously detecting an ambient air temperature value (θ a) outside of the air channel or has one such, wherein the control unit is set up to output the trigger signal at the first serial data interface if a predeterminable ambient air temperature limit value (θ Ga) is exceeded by the ambient air temperature value (θ a) or to stop the output of the non-trigger signal (BEAT) at the first serial data interface and, - wherein the thermal trigger device has a housing and a circuit carrier arranged in the housing, wherein the housing has a sensor opening for guiding a first section of the circuit carrier out of the housing, wherein the first temperature sensor is arranged outside of the housing on the first circuit carrier section and the second temperature sensor is arranged inside the housing on a second circuit carrier section, wherein when the thermal trigger device is correctly attached to the air channel, the first temperature sensor is arranged inside the air channel and the second temperature sensor is arranged outside the air channel. - wherein the thermal trigger device has an electronic control unit and a first temperature sensor connected to the control unit for continuously detecting a channel air temperature value (θ i) inside the air channel, - wherein the control unit has a first serial data interface or wherein the thermal trigger device has a first serial data interface connected to the control unit, - wherein the first serial data interface can be connected to an interface line as a third line of the connecting cable, - wherein the control unit is set up to output a trigger signal at the first serial data interface if the channel air temperature limit value (θ Gi) is exceeded by the channel air temperature value (θ i) or to stop the output of a non-trigger signal (BEAT) at the first serial data interface, - wherein the control unit is connected to a second temperature sensor for continuously detecting an ambient air temperature value (θ a) outside of the air channel or has one such, wherein the control unit is set up to output the trigger signal at the first serial data interface if a predeterminable ambient air temperature limit value (θ Ga) is exceeded by the ambient air temperature value (θ a) or to stop the output of the non-trigger signal (BEAT) at the first serial data interface and, - wherein the thermal trigger device has a housing and a circuit carrier arranged in the housing, wherein the housing has a sensor opening for guiding a first section of the circuit carrier out of the housing, wherein the first temperature sensor is arranged outside of the housing on the first circuit carrier section and the second temperature sensor is arranged inside the housing on a second circuit carrier section, wherein when the thermal trigger device is correctly attached to the air channel, the first temperature sensor is arranged inside the air channel and the second temperature sensor is arranged outside the air channel.