Help My CPU went to 144C randomly again?!?!

Now for the second time my CPU temperature has jumped up to 144C on one of my Cores. I have an AMD Athlon II x3 455 and I am using Coretemp to monitor my temperatures. For some reason, on coretemp my CPU frequency was at like 9999.33 MHz but when I check it through CPU-Z they are at there normal 3315.1 and my voltage is at 1.376, so is my voltage ok? I think it is coretemp but Im not sure so what do you suggest? Oh and I have never overclocked or done any thing of that sort through the BIOS and I have an aftermarket cooler , Zigmatek GAIA SD1283, So is there anything I should do to help? Could it have been a misreading or did it actually go to that high of a Temperature? Like I said this is the second time and they were both at the exact same temperature.