Image forming apparatus, control method, and storage medium for measuring the temperature of a fixing unit, selecting a sheet type to be used for cooling the fixing unit based on the measured temperature, and performing control so that a sheet of the selected type passes through the fixing unit when the measured temperature is higher than a predetermined temperature

An image forming apparatus capable of rapidly cooling a fixing device is provided. A fixing unit of an image forming apparatus (MFP) includes a fixing device for fixing a developer image transferred onto a sheet based on image data, a temperature sensor for measuring the temperature of the fixing device, a heater for raising the temperature thereof, and a cooling device for cooling thereof. A control unit of the MFP acquires sheet information in which information for adjusting the temperature of the fixing device is described, selects a suitable cooling sheet to be used for cooling the fixing device based on the acquired sheet information and the temperature of the fixing device measured by the temperature sensor, and passes the selected cooling sheet through the fixing device to cool the fixing device when the temperature of the fixing device measured by the temperature sensor is higher than a predetermined temperature.