Its quite common to see advice about providing water for bees but generally this refers to honey bees who need to drink regularly. We put in a pond at rosybee with gentle banks where the bees can suck the moisture from the mud at the edge of the water. Our honey bees use it daily as their main water supply but I have never seen any wild bees there. Most wild bees (bumblebees and solitary bees) seem to get their water purely from nectar or potentially from dew on plants.
This week as been particularly hot - both day and night - and one of the things I have noticed isthe honey bees are happilly foraging right through the day, even on some plants they normally don't bother with. Well, most of them are Italian in basic DNA so I guess they are more prepared for the heat, wheras bumbebees originate from the Himalayas, albeit several milleniums ago.
I am also seeing a good range of solitary bees out but the bumblebees are only out in the early morning and then I find them choosing to forage in areas of light shade and I keep finding them sheltering from the heat under leaves during the hottest part of the day.
I have never seen bees hiding from the sun before but maybe in was not looking carefully enough.