Differential scanning microcalorimetric measurements on phase transitions in water-oil-surfactant mixtures are presented,
demonstrating that this method is highly sensitive towards small heat changes connected with structural transitions in the
samples. The values for the latent heat of phase transitions are determined and the results are compared with predictions
from mean field theory, emphasizing the role calorimetric experiments can play to identify the most important contributions
to the free energy describing the mixtures. Doing this, the present status of the understanding of temperature dependent phase
transitions in microemulsions is reviewed.