Anet A8 Sensor Holder 12mm & 18mm

The question I've been asking myself for some time is what would happen if the extruder fan and the extruder heat sink where not in place. How hot would the area get? Would it effect the filament running through the threaded extruder throat? Would it effect prints in general?

Since I'm using my "Anet A8 Sensor Bracket 12mm and 18mm" (http://www.thingiverse.com/thing:1907394) I was always reluctant to dismantle that part of the extruder as it would mean that I would always have to recalibrate