[mrguyorama]

The rumor is that this is a bug that happens when you close your laptop screen to put it to sleep BEFORE you pull out the power plug, so the laptop basically never realizes it stopped being plugged into the wall, and does work it shouldn't, like a windows update. I always remove the power before putting a laptop to sleep and do not have this problem anymore.

It happens on macbooks too weirdly.

A sleeping laptop, even "modern sleep" should not be doing enough work to create a meaningful amount of heat.