I've not been into the top of this but don't believe there is a bridge.  I'm not even sure the coolant passes through the intake manifold from head to head but the gaskets are wet in that area.  The sensor feels like it may be on some sort of a stand pipe coming up out of the manifold.  It probably is something simple if I could get a good look at it.  I've got this in an unheated garage and, yes, I'm sure I'll think often of sunny beaches before I get it fixed.  I hate to pull it down for something that may have an easy fix; this is my major "wheels" so I need to get it done.