Liquid oxygen is a pale blue, cryogenic liquid that is formed when oxygen gas is cooled to extremely low temperatures, below -183 degrees Celsius (-297 degrees Fahrenheit). It is used in various applications, including rocket propulsion, where it serves as an oxidizer to support combustion. Due to its high reactivity, liquid oxygen must be handled with care, as it can cause materials to ignite more easily. It is also used in medical settings to provide supplemental oxygen for patients with respiratory issues, making it an essential component in both aerospace and healthcare industries.