There is a voltage regulator flat against the circuit board right next to the 5vdc power input.
I haven't found it to be required, but if you think it (the regulator) is getting too hot, you slide it between the regulator and the board until the two holes match. Do this with the power off! Then secure it with either a small machine screw and nut or even a very tight Tie Wrap. You don't want it to come loose and touch anything electrical.