A Creative Idea for Medium Fed Ex Box

My office was freezing for the past 2 days. I need to upgrade the air condition vent deflector. With the help of 2 tall people, here is our creative use of a Medium Fed Ex box. 

We cut a hole in the back of box the size of the vent and used the cutout as shim. Then push the box on to the vent and inserted a the shim. Add a push pin at the top to hold it in place. 

I didn't tape up the box tightly, there is still few small holes for cold air to escape for when my super hero power come on and I don't melt away.