Athlon 1.33 Ghz temperature

Hi, I have a athlon 1.33 ghz processor running on a 266mhz motherboard with 128mb ddr ram.
The temperature readings that i get from the bios is about 64 degrees celcius. and that is not even when it is on fulll load. I dare not try giving it the full load until i seek help. Is this reading too hot????

Also, could this be due to the fact that the shop that I bought it from has overclocked a slower chip to 1.33 ghz? How to I check whether my chip is in fact overclocked when i first bought it?