While much progress has been made screening common defects and outliers, less emphasis has been placed on testing for performance outliers and defects across the expected operating temperature range. The subject of this paper is an analysis of the minimum testing required to screen temperature dependent outliers at wafer sort and final test. The analysis is based on data obtained from 20 wafers of a 0.18..m skew lot and at the two temperatures 30?C and 85?C. The results demonstrate a need for defect screening at multiple temperatures and the advantage of die trace in multiple temperature testing.