Abstract: If commanders are to have the freedom to move around the battlespace to locations where they can best influence the battle at the critical time and place they must be sure in the knowledge that they can do so undetected. Infrared (IR) sensors, with ever increasing sensitivity, are now well established in the land environment. IR signature management is therefore becoming evermore pertinent in that environment. Innovative design and the use of modern materials can reduce the external temperature range of a vehicle but can be expensive. It is therefore paramount that vulnerable areas on a vehicle are identified so that appropriate thermal camouflage can be applied in the most cost-effective manner. High-fidelity thermal signature models are available but are time consuming to run and heavy on computer processing power. A simple, easy to use thermal signature model would provide a ready alternative to the more exacting complex models. Whilst not attempting to replace the high-fidelity models for the detailed analysis of thermal signatures, a simple model would have utility as a first filter of trials data and the initial testing of signature reduction concepts. A single temperature difference model of the Main Battle Tank for input into a Minimum Resolvable Temperature Difference (MRTD) model is presented. The model is used to predict detection range reduction and thereby identify the areas on a MBT that require thermal signature reduction.