The reason for the short battery and heat (the laptop got very hot under Windows) was that under Windows, the discrete graphics card was active all the time! The Boot Camp 4.0 drivers for Windows did not support switching graphics between the integrated and discrete video cards, but instead used discrete all the time. To my dismay, I found that while the Macbook lasted 6 hours or more while running Mac OS X, the Windows 7 lasted at best 3 hours.
I then installed Windows 7 Boot Camp on it. It came with Mac OS X 10.7 Lion which I promptly upgraded to Mac OS X 10.8 Mountain Lion. I recently got a mid 2012 Macbook Pro 15in laptop.