The quality of stored materials, such as food and medicines, depends on environmental and refrigeration storage conditions to ensure their preservation, stability, and the effectiveness of active components. In developing countries such as Mexico, particularly in high-temperature regions, the equipment is usually basic due to the high costs of electricity. This makes it of great interest to have a versatile application that can optimize the available resources across different facility configurations. This paper presents the development of a computer application designed to analyze temperature distribution in three-dimensional, rectangular-shaped storage facilities. With an intuitive graphical interface, users can specify various heat and cooling sources along the boundaries. The application then calculates the temperature distribution throughout the room by solving the heat equation using a finite-difference method. This tool offers a valuable solution for both government and private sector use, enhancing temperature management in small storage facilities.