Microsoft Patches Surface Book And Surface Pro 4 Sleep Issue
 

When I reviewed the Surface Book, there were a lot of bugs with the software. Some of them have been pretty minor, and Microsoft has been updating the firmware and drivers on it since before it was launched. Most of the issues have been sorted out, but there was still one issue which seemed to be elusive to the teams at Intel and Microsoft. The Surface Book would not always sleep, or, I should say, when it went to sleep it would actually use much more energy than when it was being used. Often times I would close the lid on the Surface Book and after a minute or two I’d hear the fans kick in, and the device would get very hot to the touch. This was an even bigger issue if you closed it and put it in a bag, since the bag would just trap all that heat.

http://www.anandtech.com/show/10051/...-4-sleep-issue