What is the CPU? What is the MB and what is ambient temp? It's probably one of the following:
Temp1: 43C Temp1: 45C Core: 12C
Unless your room temp is 50 °F, I wouldn't trust that "Core" temp value at all. If you have a dual core chip, it could be that your MB temp isn't displayed. If you have a single core chip it's one of those "temp1" numbers probably. What happens to them if you run orthos? One should shoot up if single core, and both should shoot up if dual core. Your MB temp shouldn't be over say 45 C unless you have a serious problem.
i am using dual core...when i run orthos, only first Temp1 is shooting up.. but 2nd Temp1 dun... does it mean that 2nd Temp1 is mobo temperature?
Stop using speedfan and try rmclock which is much better in my opinion.