The area of the diabetic foot ulcer (DFU) and its reduction over weeks is used for assessment in clinical practices; however, literature reports that this is not reliable parameter. This work has investigated the association of change in the mean temperature of the ulcers with three clinical conditions relevant to wound healing, i.e. peripheral vascular disease (PVD), chronic kidney disease (CKD) and ischemic heart disease (IHD). Thermal and RGB images of 23 DFUs of the first two weeks of ulceration were studied. One-way ANOVA was performed on the change in mean temperature of the ulcers and change in area and it was found that the weekly change in mean temperature was higher for patients with CKD (p-value=0.009). Also, change in area measured from RGB images did not show any association with the clinical conditions. The application of this work is that the temperature obtained from thermal image of the