If your laptop fans keep blowing out of control when running VirtualBox on a Ubuntu Host-Windows Guest, you might need to try one the followings fix on this article.
http://home.icequake.net/~nemesis/blog/index.php/archives/321
The one that fixed it for me is the one where I had to create a dummy VirtualBox machine and run it simutaneously as my dev box.
I was hoping with the release of version 4 (4.0.4) that this issue was going to go away but still the same result.