So two three pound packages of bees will be here, they will be hived on wax coated plastic foundation. The problem is the night time temps will be around 33 and the day time high about 50. It will be one or two days before things warm up again. So would you install the packages, or keep them inside until things warm up?? I will be using a top feeder.
if you are worried you can leave the package un-hived for a day or 2 if they still have food in that jar they came with. You could leave them indoors in a cool shaded place, mudroom or basement. It is best to get them into a hive after that.
I would of said go ahead and install them, right up till you said you were using a hive top feeder. ;)
Feed needs to be where or as close to, the queen and cluster is located.
Pull off the top, inner cover, and then place a empty box on the box with frames. Put the queen cage on the frames, next to two small wood strips there you can place the feeder can or even additional jars with VERY small holes. then dump the bees on top of the frames. Place the inner cover and top back on.
This video covers most of these procedure:
Installing bee package (http://www.youtube.com/watch?v=2bIoQGXJmrg#)
Hive top feeders have their place and use. But in cold weather, and especially with new packages, the bees do not always go up and feed and will starve to death. I had one beekeeper contact me last week of this situation here in Pennsylvania as we have had cold temps and below freezing temps at night.