Bees Coping with the High Temperatures

I keep slatted racks on all of my hives, so I don't get bad bearding even in the hottest weather. A slatted rack is the size of a hive box and has slats that parallel the frames in a regular box. It's not a tall piece of equipment - about 2 1/2 inches tall. The slatted rack provides some space for bees to hang on the slats and ventilate the hive. 

This is what a slatted rack looks like: 

It goes on the hive below the bottom box and forms the top of the entrance above the bottom board.

But in the hottest weather, even with a slatted rack, the bees also are sent outside to help keep the hive cool both by taking their hot little bodies out of the cumulative body heat inside the hive and by working their wings.

This video was made when the temperature in Atlanta was in the 90s one recent afternoon. It's in slow motion so you can see their wings.