A riser elevates the laptop to make a gap beneath it. This quarter inch of space lets hot air escape and reduces heat to the desks surface. This isn't quite sturdy enough to be a stand and it lacks any device that could make it a cooler. It's really a temporary solution for a stand designed for heat dispersal. Obviously it's less effectual than a cooling system, but more of a convenience if a cooler isn't available. This might be the cheapest, quickest, easiest way to make a gap of space, but it's also the crudest.
Step 1: Cut up the cardboard
Originally the idea was done with folded paper wedges, but thick drink coasters have also been used. These risers are cut from a piece of double stacked cardboard. The shift to a composite material uses corrugation to add to breath ability. The gutters in the corrugation aim toward each corner to guide heat away from the laptops surface area. If this were incorporated into a cooler stand, the air would be able to pass through each cardboard corner with out resistance. If a desk fan was aimed at the tables' surface, winds could still ventilate the gap but still not as efficiently as fan directly beneath it.