A work machine includes a thermostat provided upon a path that conducts the cooling water to the radiator, and that opens and closes the path according to a temperature of the cooling water, a fan device that blows external air at the radiator, an output changeover switch that changes over output of the engine between high and low, a rotational speed setting unit that sets a rotational speed for the fan device according to the temperature of the cooling water, and a rotational speed adjustment unit that adjusts rotational speed of the fan device, wherein, within a temperature range for the cooling water in which the thermostat is fully opened from fully closed, the rotational speed of the fan device to be lower when the output changeover switch is changed over so as to limit the output of the engine.