In a pilot scale wall-cooled tubular reactor, temperature profiles have been measured with and without reaction. As a model reaction oxidation of carbon monoxide in air over a copper chromite catalyst has been used. The kinetics of this reaction have been determined separately in two kinetic reactors with internal recycle. A pseudo-homogeneous reactor model without axial dispersion is used for the description of the temperature profiles inside the reactor. The heat transport parameters lambda(rad,eff) and alpha(w) have been optimized to give optimum agreement between experimental and calculated temperature profiles. Preliminary experiments showed that the occurrence of reaction seems to increase the overall heat transfer coefficient. The pseudo-homogeneous reactor model is allowed to be used, but is not adequate for the description of the temperature profiles inside the reactor during reaction.