Thermal bowing, often referred as bulging or out-of-plane wall deflection, is a common issue on sandwich panel walls caused by a temperature differential between a building interior temperature and the environment. The stresses caused by temperature changes in concrete members are widely known in the practice of bridge design, but not on sandwich wall panels. For sandwich wall panel applications, it is common to have non-composite panels when the designer expects a high temperature gradient, what yields a less economical design, but reduces the bowing. This project aimed to validate current assumptions regarding the heat flow in sandwich wall panels and to perform a parametric study of panels subject to thermal loads, varying the concrete layer thickness, panel length, type of shear connector and separation using a commercial finite element analysis software. This study concluded that current design practices either underestimate, in the case of multiplying the classical mechanics values by the reported degree of composite behavior, or overestimate the real value of bowing, by using classical mechanics. A method for determining the percentage of composite action and compute bowing was developed and recommendations addressing the importance of this type of loading were given.