Although this does not answer the question why Flash Player causes overheating, this somehow reduced my average laptop temperature by 10-15 C down to a much comfortable level 45-50 C. What I did was I opened up my laptop, and cleaned out the air intake, fan, and heat sink then applied thermal paste on CPU and GPU.
So for this instructable, I'm going to show you how to apply thermal paste and clean your laptop fan. Although applying thermal paste is a very easy process, it should be done correctly, otherwise you will not receive the optimal cooling effect that is desired.
Step 1: WHAT YOU NEED
2) Cleaning materials such as cotton swabs/balls damped with Isopropyl Alcohol. 70% solution is enough but the higher the percentage the better.
3) Other important materials like phillips/flat head screwdriver for opening up your laptop. Anti-static cleaning wipes is also particularly useful.
4) Plastic card for spreading the thermal paste.