It's mid March and one of my hives has what seems like just enough bees in it to cover the brood only. There is still some honey in the hive although on the outside edges. Also there is brood on two sides of two frames about six inches in diameter. Its still cool out- between 30-50 degrees F. I feel like I'm losing this hive. Any suggestions?
Pargyle is right and echoes my writing we obviously posted at the same time lol but you could try a couple of other things.
You could try transferring the colony to a very small nuc or mini nuc, or smaller if you have a nuc that will take your standard sized frames. This should help with heating the colony , thats one possible thing that might help. Check for stores and feed accordingly. don't give too much if you feed sirop, however this should be ok as long as the bees fly regularly. If its really cold where you are then feed fondant.
If you can find a very small frame of brood from another colony, that has lots of nurse bees on, you can give this to the very weak colony. spray any frames your combining with some other scented syrup, this should mask any problem if your mixing bees, Some would say you wouldn't need to do that at all! Make sure the queen stays in the colony the frame came from, otherwise its disaster.
Sometimes this happens. I have a couple that are small and weak but i personally wouldn't bother adding brood unless i felt it was a safe bet. The receiver colony must have enough spare bees to cover their brood and the brood you are adding.,but if your desperate to save this colony then thats about all you can do. If you have another hive that dies out, and no brood you could add the spare frame and if its got pollen in it, you should make sure the pollen side is next to the small cluster of bees you have left. There will probably be plenty of sugar or stores in the colony, its pollen they might be short of in this situation and its costly for old bees to forage for its this time of year. if they have some pollen close the queen may decide too lay a bit more and the colony should recover. Pargyle is right that sometimes if you just leave them alone, you will be surprised just how they bounce back.
Thats about all you can do.
Best of luck!!