It looks like some kind of treefrog, but without pictures from other angles its hard to tell. It appears to have a stripey sort of pattern on it's back, which makes Cuban, Cope's Gray, Pine Woods, or Bird Voiced most likely. Check out:
Identifying Florida's Treefrogs and please get back to us.
A few days at the temperatures that won't kill off a typical house plant will also likely not be a major issue for a Florida treefrog, but it was likely lethargic when removed from the truck. Dehydration is also probably not a big concern either, a truck full of plants is humidity city.