An apparatus system, and techniques for detecting temperature change are disclosed. The system includes a temperature sensitive antenna that can be included in an RFID tag device. The antenna is associated with a temperature sensitive material that, upon being exposed to a particular temperature level over a time interval, causes at least one of a change in the resonance frequency of the antenna and change in antenna signal strength (e.g., antenna gain). An RFID reader is also provided that sends commands to the tag device and determines the existence of a temperature change based on a comparison of signal strengths received on different frequencies from the antenna.