Jeekinz, that is why a laptop cooling pad would be good for you, and elevating the rear of the computer when on a firm flat surface will help. Apparently when you place the laptop on your lap the bottom vent or side vent or both are being partially or completely blocked. Both of my computers are vented exactly the same way, but I never have a problem with mine and DW's actually runs cooler on her lap. So something in the way you are placing the computer on your lap is the culprit.
A design flaw as you call it, but not a mechanical problem. My point was that those with design flaws or just wanting their computers to last longer can take steps to do so, but those with mechanical problems need to fix the mechanical problems not just cover them up or they will have more problems later on down the line.
And yes, MAC have cooling problems as well, and their laptops vent in similar ways to the way PCs vent. Otherwise they wouldn't sell laptop cooling pads specifically for MACs. Heat is a problem facing any electronics device, some manufacturers do a better job of handling it than others but all have to deal with it.