Thermoplastic materials are increasingly used as a light weight material, especially in automotive applications. The loads on these structures are often impulsive, for example in a crash situation. A high rate of loading causes a high strain rate which has a major impact on the mechanical behavior of thermoplastic materials. The stiffness as well as the rigidity of polymers increases to higher strain rates. The increase of the mechanical properties is superimposed to higher rates of loading by another effect which works reducing on stiffness and rigidity, the increase of temperature caused by plastic deformation. The mechanical behavior of thermoplastic materials is influenced by temperature opposing to strain rate. The stiffness and rigidity is decreased to higher values of temperature. To study the effect of thermal damage on thermoplastic materials, high-speed tensile tests are performed on different polymers, a semi-crystalline PA 6 and an amorphous PC. In preliminary investigations at Robert Bosch GmbH, Gerlingen, Germany, thermo-mechanical analyses of PA 6 under high-speed tensile conditions were performed. The tests were conducted using a high-speed thermo camera, showing a significant increase of temperature on the surface of the specimen which has again a major effect on the stress/strain-behavior of the considered PA 6. However the temperature can only be measured on the surface of the specimen. Furthermore the use of high-speed thermo cameras in high-speed tensile testing is very expensive. For this reason the IKV develops an approach which only uses high-speed strain measurement to transpire the link between strain, strain rate and thermal damage. The results can be used as a foundation for the development of a strain and strain rate dependent damage model for thermoplastic materials. The developed approach works completely without computer based optimization processes like inverse analysis and is only based on measured data.