Superheate water is liquid water under pressure at temperatures between the usual boiling point (100°C) and the critical temperature (374°C). It is also known as subcritical water and pressurised hot water. Superheated water referred to in this article is stable because of an applied over pressure which raised the boiling point, or by heating in a sealed vessel with a headspace, where the liquid water is in equilibrium with vapour at the saturated vapour pressure. This is distinct from the use of the term superheating to refer to water at atmospheric pressure above its normal boiling point, which has not boiled due to a lack of nucleation sites (sometimes experienced by heating liquids in a microwave).