Supercritical (SC) water oxidation (SCWO) is a potentially useful technology for destroying forever chemicals like PFAS. The physical property differences between water and SC water, particularly changes in solubilities of organic compounds and salts, are key to understanding SCWO’s potential. The nature of SC fluids will be introduced, as well as how adding an oxidant and heat can create conditions for very fast reactions capable of rendering PFAS and related compounds into simpler components. Recent demonstration projects (from Battelle, Aquarden, 374Water, and General Atomics) to use SCWO on dilute 3M Lightwater Firefighting Foam will be reviewed with particular attention on the effects of temperature.