Perhaps the greenest and most flammable case mod we’ve ever seen, aside from the UbuntuBox, the “Recompute” cardboard PC case shows off how sustainability can not only be cheap, but can ignite your whole house in flames as well.
Even if there is a cooling fan, and even if the power supply and mother board are kept at separate ends of the PC, this thing is going to generate plenty of heat.
Link
the fire point of corrugated cardboard is 258 and complete ignition temperature is 427.