Brand New IMAC 27 overheats

Question

Greetings to all from Chicago!
Just purchased a brand new IMAC (27 inch, 2.93GHZ QUAD-CORE INTELCORE I7, 8GB 1333MHZ DDR3 SDRAM - 2X4GB, ATI RADEON HD 5750 1GB GDDR5).
Previously had 24 Inch MAC (plastic on the back which is the point of my comparison. It still stand right next to the new one so I can compare.
The new Machine gets so hot that you can burn your hand. I am only running Logic Pro and Internet (same as on the old Machine). Measured via ISTAT PRO, the machine boots at at 25-28 Celsius (CPU temperature), then quickly warms up to 45-50 Celsius. It maxes out at 65-70 Celsius and stays there, NO MATTER which programs are ran. At that point, you can't even touch the top of the computer.
By contrast, my old IMAC 24 inch, stays cool, noiseless and never goes beyond 40-45 Celsius, when the same apps (Logic + intenet) run.
What should I do? Are all new IMACS like this? Is this because of the aluminum back? Shall I return it and wait for next year's model? Exchange? Repair? ( I have Apple Care). Here is how Apple advertised the new IMACS:
Cool, quiet components
"The widescreen iMac display allows more room to separate the two hottest components, the CPU and the GPU. This keeps things cool inside the iMac enclosure. Apple engineers also implemented an intelligent control system that monitors temperatures and delivers just the right amount of airflow to critical components. And the three fans inside iMac have been tuned to be ultraquiet. The result of all this tinkering with heat and sound? A system that operates at 18 decibels when idle — so quiet, you hardly know it’s on.*
Well, the reality is that it is a lot nosier and heats up a lot more than the predecessor, unless I have a defected unit.
Thanks in advance for all the input and recommendations
Cheers,

Answer 1

the components of the imac ARE cool & quiet, compared to other components. but don't make the mistake to think this means the imac is cool: it's an all-in-one-design, which just means it will get pretty hot, that's only natural. still, compared to normal computer components, the imac hardware is pretty cool, but that doesn't mean the case has to be cool. mine can get pretty hot too. I don't burn my hands, but it's painful to keep the hand on it.
as for the temperatures: 40-50 degrees celsius are normal for the CPU temp, everything above seems unnormal to me when your computer is idleling. what you didn't mention was your air temperature. are you dealing with hot weather currently?
anyway, also make sure in activity monitor no process is running wild and uses CPU. remember that the i7 has 8 cores, so 12% CPU usage actually means that one core runs at full speed!
besides that, if you have normal weather and no process runs wild and your CPU temp still goes over 50 degrees, I would call apple and they will likely exchange your imac