Although the reactants are stable at room temperature, when they are exposed to sufficient heat to ignite, they burn with an extremely intense exothermic reaction. The products emerge as liquids due to the high temperatures reached. Since thermite reactions require no external source of oxygen to burn, they cannot be smothered and will ignite in any environment.
Thermite reactions have many uses. Thermite grenades and bombs are used in combat as incendiary devices, able to burn through heavy armor or other fireproof barriers. Thermite can also be used for quickly cutting or welding metal without requiring complex or heavy equipment. The reaction has also been used to purify the ores of some metals, e.g. uranium.
The most common thermite reaction is that of iron oxide, which exceeds 3000°C:
Thermite should not be confused with a thermal lance.