About getting hot...it's normally that your whole phone gets hot as it didn't enter "deep sleep" but that's really strange that that dot is more hot than other screen parts as the screen is just a very thin glass over a kind of steel to reflect light, that steel plan surface is just above the main board which leaks heat so it means that there is a direct contact between the main board and the screen on that faulty part "maybe because you have pressed on that part too much"
anyway to make sure that apps in not the problem, try to turn off WIFI and reboot in safe mode or at least turn off sync and other apps manually "as your phone has entered deep sleep only for 17m while the processor keeps running at highest level 1ghz for along time".
لا إله إلا الله...محمد رسول الله
Atrix 2 at&t
>>> SlimKat >>> System1 (Main usage)
>> R.I.P Symbian