Stepper motor of second extruder gets hot but is not used

Hello. Im bit surprised to find out that the extruder stepper motor of the second head is nice hot (50°C). But i use only extruder/head one. Where the motor is 10°C colder. As per display is the second hotend cold, as it should be.

I added already an heat sink to the servo motor, to increase the live time.

I know, a stepper motor is able to handle a lot more heat. But its just an one hour print. What will happen if i run a full day?

I guess, i should add some heat sink everywhere :-|.