A radiator is a device used to transfer heat from one medium to another. Radiators are commonly used in heating systems, where they are used to transfer heat from hot water or steam to the air in a room. Radiators can also be used in cooling systems, where they are used to transfer heat from the air in a room to a cooler fluid.
To turn off a radiator, first locate the radiator valve. The radiator valve is usually located at the bottom of the radiator, on one side. Once you have located the radiator valve, turn it clockwise to close it. This will stop the flow of hot water or steam to the radiator, and the radiator will begin to cool down.