I would believe so. The ambient room temperature for me is usually 68-70 F, so my idle temps in Windows is around 60C. You can also adjust the fans using SMC Fan Control in OS X before you switch to Windows to try to help cool it.
Sometimes it's around 55 C on idle, but not often. It's Windows.
Battery life on Windows sucks, roughly half what you'll be able to get in OS X, all due to poor power management. I don't honestly think the fan speeds/temperature affect battery life all that much, what causes said fan speed and temperatures does.