Many users of Mac laptops, and even the most devoted fans of the Apple brand, would contend that MacBooks can be really hot books. Designed to cool in a very similar fashion as most high-powered PC laptops and often with similar components too, Macs tend to be faster than PCs in head-to-head or lap-to-lap testing. A 2009 Popular Mechanics user and performance test found that functionality wasn't much different in either desktop or laptop usage, but Mac came out strong in speed, with an average startup of 28.7 seconds to the PC's 1 minute, 13 second average [source: Derene]. Some PCs are faster than some Macs, and vice versa, but Macs do typically have a reputation for speed and multitasking plus great design.
If you picture tiny mice running on wheels, it's easy to imagine that they get hotter the faster they run and it's not hard to imagine the inside of a laptop as filled with little wheels and oscillating fans and machine parts being taxed to the limit by the amount of work or play you're doing. While there is a fan operating in much the same way as any rotating fan would work, heat in a laptop has more to do with how close everything works together, with parts configured to fit and each part working hard to draw on power and perform. Parts aren't so much whizzing and moving as they are sucking in and shooting out energy and information.
Faster-performing machines will pull lots of energy into their components, and as each part does its jobs next to another part doing its job, a great deal of heat energy is produced with nowhere to go but out into a person's lap or work surface. Keyboards might get warm through friction with the fingers, but because the raised touch pads have at least a little give up and down and the flat ones have a layer of circuitry underneath, much of the heat in a thin laptop has nowhere to go but out through its vents and down into a person's lap or work surface, where it's absorbed or reflected.
Is the heat in the speed? Yes and no. Many in Mac forums online would say it's the size of the processor that enables the high speeds, but that also can kick the fan into high gear, making it loud and draining the battery. Others complain about the computer casing and even hot keyboards. Sometimes the aluminum casing on MacBook Pros takes the heat in discussions and even screen brightness or high resolution seem to up the temps for other users.
Some owners of Mac laptops report no problems while others experience overheating during simple tasks like surfing the Web and creating documents. So is the computer or the user the problem? Maybe a bit both.