I had a simular experience tonight. I received some packages today and went out to hive them, it is about 48f out with some rain and wind. I put them in the house for a while to make sure everything looked alright. Two of my sons came home from school and we grabed 4 of the packages and headed out to the back yard to hive them. The first one seemed slugish, the next two really slugish, and by the time we got to the 4th and opened up the package to look at the queen, I said to the boys she's dead and brought the package back in the house. Left the queen cage out of the package and was looking at her at the kitchen table, when all of a sundun she started to move, with in a few minutes she was moving around like normal. The workers in the package did about the same thing, all fell to the bottom and then once they warmed back up are doing fine. I went back out to check on the packages we just instaled and they are just laying in there dead looking, most on the bottom board yet, with some activity. Ive been keeping bees for 28 years and that is the first time I've ever seen that, but maybe the wind chilled them, got me a bit worried, hopefully they'll warm up enough to get around the queen to keep her going. I have the rest of the packages still in the house. I'll take the truck this time and keep the heator going, grab the packages while warm, dump them in and see what happens. One thing that may have something to do with it is the syrup cans were empty, wonder if they were just week and lacking in energy to produce heat.
As wonderful as this life is, there are days I really look forward to the next. :)