Pressure injuries are skin injuries caused by persistent tissue compression, making it challenging for the Public Healthcare System. In this context, technological resources like thermography can be implemented to obtain additional information about the injuries. However, there’s no precise mathematical description of the functions that model these injuries, just of its physical indicators. This study aimed to evaluate the behavior of the level curves and the pressure injuries’ thermal gradients. Thermal images of the injuries were analyzed with the help of the software R, and Pennes Equation was used to model thermal gradients on the skin’s face. As the main results, we noticed that hardly visible skin regions were amplified by the level curves and gradients’ observation. This modeling can contribute to thermographic analysis with the possibility of indicating risk areas of future new injury development and promoting the follow-up of the evolution of the injuries.