Aluminum Imac Burn Marks

[javtan]

I bought My imac on Christmas Eve last Year (2.4GHz). Today while i was cleaning it, i found a 6" Black line on the top left part of the imac. (next to microphone). The line can be seen only from an angle. The top left part of the imac always gets very hot.What must i do?

 

[chadrob30]

The iMac vents heat from the upper left corner. Do you smoke next to the iMac?

 

[javtan]

definitely not