i have the e6420 with the P5N-E SLI and air, and when i use everset, Speedfan, or even check BIOS, i always have a really low temperature. i just got done playing F.E.A.R. for about 45 minutes and my CPU is 29 degrees. its also overclocked from 2.13 to 3.2
long story short, i think its just that the c2ds really dont put out that much heat