I didn't look on purpose, the Nuc was blown over in a gale and I was somewhat surprised to see how well they were doing.
I treated some of my hives last year after what I considered to be a two week period of cold weather and was astonished at how much dead brood was taken out of the hive. The hives that were treated with acid were slow to build up in the spring and took until mid summer to really get going. Apart from the enjoyment the bees give me, they have to as far as possible pay their way, I cannot afford to have hives that don't produce a good crop.
There may have been other factors going on but this has made me very wary of subjecting them to it again. I must point out that I take great care to ensure my hives go into winter treated and fed as thoroughly as possible.
If I had one hive and I was concerned that I hadn't treated properly then I might treat with OA. If I had treated properly and they appeared okay, I would leave them until the weather warms up and then if they need it treat with either thymol before the honey flow started or consider using macs. If it was seriously infected then I would look at emergency treating with Apivar.
S