From the skeinforge help files (in the cool section)
"The important value for the cool preferences is "Minimum Layer Time (seconds)" which is the minimum amount of time the
extruder will spend on a layer. If it takes less time to extrude the layer than the minimum layer time, cool adds orbits with the
extruder off to give the layer time to cool, so that the next layer is not extruded on a molten base. The orbits will be around the
largest island on that layer. If the area of the largest island is as large as the square of the "Minimum Orbital Radius" then the
orbits will be just within the island. If the island is smaller, then the orbits will be in a square of the "Minimum Orbital Radius"
around the center of the island."
Seems pretty set for me.