A method of making an infrared detector assembly (10) with integrated temperature sensing comprises forming at least one IR sensitive element (12,14) on a substrate (16) and forming conductive electrode pads (22,24,26,28,30,32) for (a) IR sensitive element and (b) at least one thermistor (34) on the substrate. The conductive electrode pads and the IR sensitive element are in a centerline symmetrical configuration in which the conductive electrode pads and the IR sensitive element, taken together, are centerline symmetrical about at least one axis (36,38) in a plane of the infrared detector assembly, wherein the centerline symmetrical configuration is operable to reduce a thermal lag time between a temperature of the at least one thermistor and a temperature of the IR sensitive element during temperature transients. Each of first and second thermistor conductive electrode pads (30,32) has two pad end portions (40,42) spaced from each other and joined via a pad mid-portion (44) that comprises a thermal loss reduction member.