Cryogenics is the scientific study and application of materials and processes at extremely low temperatures. It involves the production and behavior of materials at temperatures below -238°F (150°C), at which point gases like nitrogen and oxygen can be liquefied. Cryogenics has various applications in the fields of medicine, energy, and space exploration, among others. Some common examples of cryogenic technologies include storing biological samples, producing superconductors, and using liquid hydrogen and oxygen as rocket fuels. The most common cryogens are liquid nitrogen (LN2), liquid oxygen (LOx), liquid hydrogen (LH2), liquid argon (LAR), liquid carbon dioxide (CO2), and liquid helium (LH2).