The authors study the operation of carbon nanotube thin-film transistors (CNT-TFT) at elevated temperatures. Due to the small bandgap of semiconducting carbon nanotubes, CNT-TFTs are not suitable to be developed as high-temperature devices. However, CNT-TFTs will still have to endure elevated temperatures when employed in large-area and flexible electronic applications. The temperature range that can be expected in these applications is well below 100°C. In this work, the authors demonstrate that even at 100°C, CNT-TFT devices are operational but with a reduced ON/OFF ratio. Beyond 100°C, the ON/OFF ratio degrades rapidly.