This cold blast and chilled brood

This last remnants of early spring is on its way out. The cold weather may have affected your colony. In the warm days preceding the cold snap the bees had expanded their brood area in the hive. Eggs and brood are becoming widespread. Most beekeepers should have their second boxes on by now. The cold may have caused the bees to go into a tighter cluster. This may have pulled them off some of the brood. It would not be surprising to see the bees in the up coming days hauling dead brood out of the hive. Or if you see some dying larvae in your hive it is not a disease. It is chilled brood. Chilled brood happens when the bees can't cover all of their brood in cold conditions. It also happens when beekeepers in early spring doing hive inspections, put their brood boxes on end instead of parallel with the ground. A cold breeze can whistle through the box and chill the brood in the frames. Keeping the box parallel with the ground helps prevent this from happening.
Chilled brood can set a colony back a little but the bees will recover soon.