In this study, the effects of pressure and temperature on pressure ulcers is investigated by using both numerical simulation and experimentation methods. Indeed, a biomechanical buttock-thigh tissue model is constructed along with wheelchair seat cushion. A human buttock-thigh model is created to perform thermo-mechanical simulations using the finite element method (Abaqus software). In parallel, experiments are conducted to determine the value of the pressure and the temperature distribution of the subject sitting on the wheelchair cushion (pressure pad and infrared camera). The preventive measures and appropriate treatments for people using a wheelchair or those with disabilities are measured. The findings show that the use of a wheelchair cushion reasonable for better distribution of pressure, decrease shear stress and improve the heat transfer between the contact surfaces of human buttock-thigh tissue and wheelchair cushion (reduce the temperature in the contact area). It contributes to the prediction of factors that can cause pressure ulcers to improve comfort seating and the quality of life for people with disabilities.