Why doesn't the Nokia 1520 have no type of vents to let out the heat. Which we all know what happens with heat to the CPU and the frame rates drop cause of the heat. Did they forget to put them in or just forgot period. Just because I know other phones have a hole on the top of the device to let some heat out.
Just about no phone I know of has vents meant for cooling. I think you may be mistaken, unless you can correct me and point to actual devices.
There was one chinese one whose claim to fame was liquid cooling..
but no other
but anyways, the chips in just about any phone today run cool enough to be cooled passively. (not saying they run cool, just cool enough so they wont die)
of course, some are defective and overheat, although I dont see them much.
so no they didn't forget or anything, its just never done anyway for phones and many tablets.
but still, heat dispersion is still a thing,although its not much of a problem I believe.