tjmax for q8xxx is 100 C.
Your core 0 is much higher than the others as program is single threaded.
While the tjmax is 100 c I think you will find that most users would recommend using a better HSF if temp is at or above 70 C (Stock HSF = poor - being polite).
My room temp is approx 79 F - My E6400 does not go above 60 with prime 95.
My I5-750 is also below 60 C (prime 95). I do not even install INTELs HSF, when I build a system I automatically order a 3rd party HSF.
First link to tjmax, 2nd link to discussion on temp.http://www.anandtech.com/show/3424http://www.overclock.net/intel-cpus/294212-what-safe-temps-e8400.html