It be great if you could get the CPU temp sooner than that, 5 secs after powering on, in teh bios.
But even so: NO... the CPU cannot realistically get to 50C from room temp in 15 secs but still max out at 67C
Assuming your rooms is at 25C or less, the CPU could only reach that sort of temp so fast if there was no heatsink, or very poor thermal contact between the CPU and the heatsink. Either way ot would keep on going up, and probably have fried long ago.
How to tell...
1. Try to get a temp reading closer to power on. 2. See what the heatsink temp is after the computer has been on for a time. Even putting you hand on teh heatsink (carefully) is enough. 3. Download Prime95. Run the machine for 15 mins and take the Idle CPU temp. Run Prime 95 for 15 mins and take the Full Load CPU temp. If teh difference is 10C or less that's fine.