idle temps arent half as important as peak temps... do some stress testing with orthos and if the temp goes over 60 after 5 mintues them it's running to hot.
if you aren't overclocking u can also undervolt the cpu
On a hot day where ambient temps are 30C, your CPU should run about 15 - 20C hotter than ambient. At load it will be in the Mid 40's to mid 50's Idle should be upper 30's. My 65nm 2.4ghz runs a little hotter than the 45nm 2.3ghz on stock speeds. But my original CPU cooler on stock speeds sucked terribly. I got a coolermaster V8 on it now and run in the 40's on a hot day at a 3.0ghz OC. The stock 2.4ghz runs hotter on the standard cooler than my OC'd 3.0ghz with the V8.
So on the q6600 @3.0ghz on a 32C ambient temp, my Idle temps are about 40C. So I run about 8C hotter at idle and about 20C maxed out (with prime95) - this would be with stock voltages.
If you are talking about the Intel E6550, mine (with stock cooling) runs at between 30-35 degrees idle and goes up to about 60-65 under load, even when overclocked to 3.2 GHZ the temps never went over 70. I have noticed two things that after time cause my idle temps to rise, very dirty heat sink and heat sink paste getting old this only ever made about a 2-3 degree difference though so nothing spectacular... Hope that helps