Well for starters, its not exactly cool. How could the Macbook not have a fan? The temperatures the device operates mostly in equal the optimum operating temperature at which it would neither feel very hot nor would it hamper the performance heavily (atleast that’s what they tell us).
How does the Macbook remain cool then?
The 12-inch MacBook and its iterations are cooled by what is called as passive cooling. Since the MacBook is a unibody aluminium device (which means that it is constructed with a single block of aluminium), it uses its chassis as a heat spreader to dissipate the internal heat to the environment.
The simple physics that “metals conduct heat better” is at play here and the aluminium performs an excellent way of dissipating the heat and cooling the laptop passively using the device’s entire body.
With all that said, the fact that Apple went fanless was to keep the MacBook’s profile thin might be fascinating, but that doesn’t automatically make it better. We recommend that you keep the device in a raised position in a way that the bottom gets adequate air circulation to keep the backplate cool.
We also recommend using Notebook coolers such as the “Cooler Master NotePal X-Slim II” which aid in bringing the aluminium bottom to operable temperatures much quicker by enhancing the air flow.