Dehydration Cause Concussion

Tuesday I go to the apiary for a visit "serious" after treatments with bees antivarroa life and Apiguard var.
start from the family that first treatment was the strongest, to see if it was collapsed (as had happened to me last year) due to varroa infestation, or which are still well populated.
take off the lid, open the coprifavo and I find the hive full of bees. good!
a little puff 'of smoke, I get close to the diaphragm and immediately remove the bees get nervous, railing against my hands, the smoker, lever
... with a little 'difficulty I extract the diaphragm and placed it beside the hive, I rapprochement with hands to extract the first frame and a cloud of bees comes out against me, slowly I moved away a few feet so calm down and after a few seconds and a hearty puff of smoke, I repeat the operation. nothing to do, and so I get attacked again two more times.
decides to close everything and try with another family.
precaution to avoid negative excitations bee stings change gloves plans and uncover the weakest family apiary.
same situation, nervous and aggressive bees. was unnecessary continue. I close everything and sadly I put the gear and I'm going home.
I can not tell what caused this sudden irritability by families who had never experienced this aggressive nature. I think I can rule out a genetic trait and I am inclined, however, due to external causes.
strong infestation of Varroa strikes me as odd, I finished treatment 10 days ago, difficult to envisage an infestation such as to compel the bees to this behavior.
imports: rape and chestnut make nerve bees, but bees are in the area where there are these plant species and, above all, this is not the time of year when in bloom. but maybe there are other flowers that make children aggressive bees, wasps and hornets ...
: friends of the forum blame for attacks of these insects the nervousness of the bees. could be and I was foolish not to install the traps that I bought this winter.
I also thought of some treatments on culture, but in the area at this time there are only the vines that are definitely not having processed the harvest in progress.