Within an emulsified combustible drop, micro-explosion is defined as the sudden vaporization of water drops inside the continuous phase, i.e. oil. Past studies have shown a relationship between the superheat temperature reached by the emulsion and the radii of inner water droplets. This raises the question of the heating history and the observed water coalescence prior to micro-explosion. The experimental set-up consists in a Differential Scanning Calorimetry (DSC) measurement device. To investigate water coalescence, the present study compares previous DSC micro-explosions of emulsion drops to oil drops containing a unique, bigger water droplet. It results that the unique water drop and the allegedly coalesced water drops exhibit the same behavior concerning superheat temperature. This thermal behavior is in agreement with the water coalescence just before micro-explosion, that was visualized in other studies. (C) 2016 Elsevier Ltd. All rights reserved.