> Intuitively, I agree but I can't find any science dealing with how a brief disturbance of the cluster would do any lasting harm. 

In my first post on this topic I offered:

> Opening the hive and disturbing the cluster to collect bees in cold weather can be detrimental to the colony, and may even kill it. --Stevenson, J. H. (1966). A Method of Obtaining Active Worker Honeybees in Winter for Experimental Use. Journal of Apicultural Research, 5(1), 63-64.

> Factors against winter treatment are the bad effects of disturbing the winter cluster of bees and the difficulty of observing the reactions of the bees to the chemical substance. -- Guy D. Morison Ph.D., M.Sc. (1931) Comments on Chemical Treatment of Acarine Disease, Bee World, 12:8, 89-90

Both of these sources refer to the potential harm to the colony of disturbing it in winter as if it were a known fact. Going back in time, Burton Gates states in 1914:

Good beekeepers know that it is not well to open a hive in winter, but perhaps few realize the resulting effects on the colony.  

In the course of the observations on this colony it was found impossible to disturb the colony in the slightest degree, even to remove and replace a thermometer, to jar the colony, or to puff smoke in at the entrance, without notice ably affecting the temperature. These effects, as in the case of opening the hive, were not always temporary, but sometimes lasted for hours. Any disturbance resulted in an almost immediate rise in the temperature, and was appreciable throughout the cluster. 

On March 12 the colony was opened for 15 minutes at 1 o'clock in the afternoon. The thermometers throughout the hive and even the one below the frames to some extent registered an immediate rise in temperature. When the hive was closed the cluster was soon reestablished but it was several hours before the temperature in the margins of the cluster became normal. On the interior of the cluster, however, the excitement and its effects were not so soon overcome. The curve for c shows that not until the next day did conditions approximate normal; the effects were appreciable even the day following the opening of the hive. 

These results agree with the experience of many practical bee keepers, who consider it unadvisable to open their hives during the winter.  

Gates, B. N. (1914). The temperature of the bee colony (No. 96). US Dept. of Agriculture.

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