The High Speed Civil Transport (HSCT) will be exposed to elevated temperatures during Mach 2.4 supersonic flight. While not as extreme as those encountered in other high speed flight efforts (NASP, Shuttle), thermal effects will impact decisions in almost all areas of material selection and design. Accurate temperatures are required to evaluate materials, structural concepts, cooling requirements, etc. Analyses show the importance of structural configuration, use of fuel as a heat sink, and surface properties on structural temperatures. Capability to accurately determine convection and radiation boundary conditions is important for future HSCT design.