Well I had a thread regarding my GPU getting heated up months ago. I was not able to solve the problem. It would go upto 110C.
I tried everything from cleaning my case and also applying thermal paste in the GPU but nothing helped. People suggested I should try installing case fans etc. but I thought that would not solve the issue as my GPU was getting heated up to a very extreme extent. Moreover, if it was airflow issue, then it should have affected other components too in my CPU which did not happen. My core temperatures etc. were fine.