Hardly a new idea though, back in the 1970's on one of the first large scale computer servers aka mainframes I worked on, we used to store Chinese and Indian takeaway inside the server for 4-5 hours to keep it warm on evening and night shift. The scary thing, back in those days microwaves didn't exist!
The IBM 370/145 was a T-shaped server, laying on its back, the whole top of the T was largely empty, ready in case you wanted to upgrade to a 370/148 or 155(I think). So it became common place to store stuff in there that you wanted to keep warm and dry. Ideal for takeaway and girlie magazines(so I'm told!).
See the youtube video here.