Because of the multiple scattering effects, the propagation of a radiative wave within an absorbing-scattering material is a very complex process which can moreover be influenced by the temperature of the propagation medium. We developed a setup to better understand the radiative behavior of fibers-reinforced polymers at high temperatures and at three different wavelengths of interest. The setup is composed of a high-power CO₂ laser source to rise the temperature of the specimen as homogeneously as possible, and of a multi-channel low-power fiber laser source to assess the radiative parameters of the material at 635, 1070 and 1550 nm. The temperature of the sample is continuously controlled during the measurement and can reach up to 450 °C with heating rates as fast as 500 °C/min. Normal-normal and normal-hemispherical reflectance and transmittance data for various polymers will be presented in this study, and the influence of the different physical changes due to high temperatures will be discussed.