The increase in process parameter variations and off-state current for deep submicron complementary metal oxide semiconductor (CMOS) technologies makes conventional (single threshold) IDDQ testing ineffective. Delta IDDQ testing performed at two temperatures for a given test vector and called ‘thermal delta IDDQ testing’ is a more attractive alternative and is investigated by the authors. On the basis of statistical Monte Carlo simulations and industrial data, it is shown that lowering the temperature from 330 K to 280 K results in a more than ×100 reduction of IDDQ mean value and approximately ×15 reduction of IDDQ standard deviation of defect-free 0.18 µm CMOS circuits.