Conditions on the underside of a vehicle often result in unacceptable temperatures for typical composite materials. Most high temperature automotive composites are only capable of withstanding 250 - 400°F, while undercar temperatures can be as high as 1100°F. These high temperatures mandate the use of thermal protection for undercar composite components. This report presents the necessary design considerations for these components. Ford's development of a composite crossmember will be discussed as a case study.