I just assembled a new machine. Decided on an i7 970 chip, 12G RAM, SSD hard drives, massive power supply and back up, and a great motherboad. What makes everyone laugh, is that I only spent $100.00 on the video card. I'm a trader, not a gamer - whatever that means
I own several laptops and have never had an overheating issue. Purchase quality goods and you get what you pay for.
I've had three apple laptops, the last two Powerbooks in the aluminum case (which I had thought to aid in temp control). The problem is that I was constantly running the chip to 105C, which is way beyond the correct operating temp for long term life of a computer and its components. I've never recorded my tower going over 58C, and it normally runs at 45-48C on a full load with all 6/12 cores running 80%+. Not to say that all laptops will do this, but it's a lot of power consumption for such a tight area, physics applies.
I have a DELL LATITUDE D830. I put Bluetack to elevate the peg-legs about a centimeter or two, and ever since then I have had no problem with overheating.