is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. In this paper, infrared thermography is used to propose a simple quantitative approach toward understanding the thermal behaviour of a liquid-liquid biphasic millifluidic droplet flow under isoperibolic conditions. It is shown that due to the isoperibolic boundary condition, the thermal behaviour at the established periodic state can be managed according to different orders, i.e. either a continuous or fluctuating contribution. A complete analytical solution is proposed for the complex problem model, then a simplified model is proposed. Finally, a simple homogeneous equivalent thin body model approximation with a characteristic coefficient function of a biphasic flow mixing law is sufficient for describing the thermal behaviour of the media under isoperibolic conditions. From this theoretical validation, the experimental results concerning the behaviour of a biphasic oil and droplet flow are presented. An analytical representation law is proposed to quantitatively estimate and predict the thermal behaviour of the flow. Moreover, it is demonstrated that with this new method, the thermophysical properties of the phase can be estimated with a deviation less than 5% from that reported by the suppliers.