I am wondering if perhaps it's a heat rash of sorts or something. He has spent a lot of time outside the last few days (three trips to the park) and has been lethargic (although that is his normal personality) and it's already 86 degrees out here already (which I believe is slightly high for NY state). Also, I gave him a bath the other day after our first trip to the park because he jumped into a sort-of filthy lake to cool off (which I can imagine being the cause of all this), which hopefully would have not only cooled im off, but got rid of whatever filthy-ness was in that lake.
I suppose the vet will figure it all out this evening for us, but I'm hoping for a little bit of an idea of what to expect.