6 degrees but still wasps!

The thermometer in my garden scaled to 6 degrees by lunch time. The morning was cold and wet! I have checked all my sites and hives this morning, all were okay and still had fondant, but the blocks had been eaten away from the hole in the crown board so I moved the blocks to put the remaining fondant above the hole. In many the bees were clustered and any movement was small and slow. One hive fooled me, indeed I thought they had perished and I removed the crown board to see what remained; as I did a rush of awakened bees came storming up into view. I quickly replaced the board and closed up.
The hive that fell over the other week was stable but obviously still very defensive. As I carefully lifted the roof to check the fondant, the bees came flooding out of the entrance. There was plenty of fondant and so I was able to replace the roof and walk away!
Despite the cold and wet (and frosts earlier this week) there was still the odd wasp flying around, seeking to sneak into the hives at two of my sites. Do these critters ever die?!