Cryogenics is the study of materials at extremely low temperatures, typically below -150 degrees Celsius. This field explores how substances behave when cooled, allowing scientists to understand their properties better. For example, when metals are cooled, they can become stronger and more conductive, which is useful in various applications, including electronics and superconductors. One of the most exciting uses of cryogenics is in the preservation of biological samples, such as cells and tissues. By freezing these samples using liquid nitrogen, researchers can maintain their viability for future studies. This technique is also used in the preservation of human organs for transplants, making it a vital part of modern medicine.