Sun or...Not...?

• I hear and see from a lot of people, oohhh, the bees need sun.  You don't want them in shade.  But then I read and hear of overheating in sun, comb collapse in sun, etc.  I think my location of some sun in the morning and some here and there as the day goes by, but never really full, is the best of both worlds.
• And also have read, the opposite -- why do bees need sun?  If they are making their hive in a wall, or an old tree stump in a forest, isn't it likely those are shady areas, at least for the forest?