Dry ice is the solid form of carbon dioxide. It is extremely cold and has a temperature of -78.5°C (-109.3°F). Dry ice is widely used as a cooling agent in various applications including transportation of perishable goods, preserving food during power outages, creating smoke or fog effects in theatrical productions, and in scientific experiments. It is called dry ice because it changes directly from a solid to a gas without passing through a liquid phase. When dry ice is used, it changes directly from a solid to a gas, giving off carbon dioxide, which can be dangerous if used in an unventilated area.