1 INTRODUCTION
2 SAMPLE AND DATA REDUCTION
2.1 Low redshift sample
2.2 High redshift sample
3 ANALYSIS
3.1 Membership determination and velocity dispersion measurements
3.2 Fitting the velocity dispersion – temperature relation
4 RESULTS
4.1 Evolution of the slope and intrinsic scatter
4.2 Evolution of the normalisation
5 DISCUSSION
5.1 Comparison with previous results
5.2 Description of simulations
5.3 Comparison with simulations – Fitting with no evolution
5.4 The effect of biased slope measurements on the evolution of the normalisation
5.5 Comparison with simulations – Fitting with evolution
6 CONCLUSIONS