Windows 8 : Hibernate Vs Sleep
Thankfully Microsoft has not removed the hibernate option in Windows 8 - you just have to search for it under the many menus and you will find it or just follow the steps in this article and you will be there in a minute - http://www.addictivetips.com/windows-tips/how-to-enable-windows-8-hibernate-option/
The option to find the menu to hibernate is quite hidden and a pain to do each time so what I have done is configured the sleep button to hibernate. Now I have no issues with my battery and my laptop does not feel like a heater each time I put it on. The hibernate option is much improved in Windows 8 and my laptop is able to hibernate in less than 10 seconds.