Superheating The superheated liquids are less stable than their vapour, while their criteria of internal stability are met. They can be produced when an increasing T or a decreasing internal P (including negative pressure, or liquid tension) beyond the stable values is produced in liquid in such conditions that vapor does not nucleate. This nucleation suppression can be reached in nature either during a short time by a very rapid P or/and T variation (phreatomagmatism, for instance), or by decreasing the air humidity at a liquid-air interface located in infra-micronic container (soil capillarity, for instance). The method of choice to experimentally probe superheating is the micro-thermometry of fluid inclusions [1], that can be designed in terms of composition and density of occluded liquids (in quartz). Their volumes are intermediate between macro-systems, in which superheating is restricted to low tensions with very short lifetime, and nanosystems, wherein the host matches the size of the critical vapor nucleus. Properties and behaviours of interest