Decay of effective temperature (left panel) and thermal bolometric flux (right panel) with time for the XMM-Newton observations of EXO 0748−676. The dashed and dotted lines show the fit to a exponential function and a power law, respectively. The XMM-Newton, Chandra, and Swift points are represented by black circles, dark grey squares, and light grey diamonds, respectively. The XMM-Newton points are the values obtained for case 4 in Table 4. The Chandra and Swift points have been taken from Degenaar et al. (2011).