I have a fix but the fix is for keeping your phone performance whether the phone is hot! Nothing can't be done to solve heat issue if u want to have a good performance!
The system is design to reduce heat once the cpu temperature is 55 Degree centigrade! It will clock ur cpu frequency to 810mhz to cool down the phone, but produce lag during game play or scroll!
However we can manage to change the point where it clocked down cpu frequency to whatever you like!
I've change mine to 65 degree then it will clock down the cpu!

To do it is to go to system/etc look for thermald-semc.conf
Modify through root explorer:
Iook for this
[MSM_THERM]
sampling 10000
thresholds 49 52 55 58 70
thresholds_clr 45 50 53 56 68
actions lcd lcd cpu lcd shutdown
action_info 192 128 810000 64 0

I've changed mine to:

[MSM_THERM]
sampling 10000
thresholds 49 52 65 58 70
thresholds_clr 45 50 63 56 68
actions lcd lcd cpu lcd shutdown
action_info 192 128 810000 64 0

It will no longer laggy once it hot! Until ot reaches 65 degree! It may be dangerous!
But so far, nothing happen to me! And i can play temple run brave smoothly, while before it'll be laggy in 5mn of game play!