This paper presents a novel temperature sensing system using amorphous indium gallium zinc oxide (a-IGZO) thin flim transistor technology for the first time. The system is composed of temperature sensing matrix, low pass filter and a comparator to sense the increase in temperature beyond the reference value. As an example human body temperature detection is demonstrated with a single bit output, where the reference temperature is 37°C. The proposed system shows a resolution of 0.1°C with a supply voltage (VDD) of 4V and power consumption of 210W, at a clock frequency of 100KHz. The comparator employs bootstrapped load in the latch to enhance the performance, showing a resolution of 0.15mV with the same VDD and clock frequency. This system finds potential applications in flexible biomedical healthcare devices and in smart packaging to monitor the temperature of critical items like medicines and provide useful information to the end user.