Sandra reports 53.C Power/Aux temperature

[winr]

I have an ECS K7VTA3 rev. 8c, XP2200+ cpu and a 350 watt power supply.

Sandra shows my temps as this.

Board temp: 31.C
CPU temp; 35.C
Power/Aux temp: 53.C

Is the 53.C too hot?

This is idling, with 1% cpu usage.

This is not in a case yet, I am testing before installing it.
It is also cool in the room and nothing is blocking airflow.