I have had my XPS 15 for around 8 months and have seen this issue arise 3-4 times. In rare instances, after closing my device it begins to heat up until uncomfortable to the touch on the entire bottom side. this occurred twice while in a backpack which caused the device to become painfully hot. when opened the power is significantly drained but otherwise opens to the windows unlock menu as normal. During regular use, the device never heats up and is just somewhat warm when playing games. I am worried that the heat could be damaging to the laptop. Is this a known issue and is there any fix?