We used to go squirrel hunting when I was in my 20's and after killing them, they hung upside down at our belts for hours too. Differences are: (1) they bled out like someone already mentioned, and (2) it was cold outside. They never were in a place over 40 degrees. Same I'd bet for that other game that had been shot and done later. Maybe not 40 but certainly nothing like what would make one die from the heat.
I wouldn't eat those chickens either.
I wouldn't eat those chickens either.