Temperatures like that may make your bucks temporarily sterile in case you had any litters planned. We have the hutches with white roofs and under shady trees, but it never hardly ever gets that hot around here.
ice bottles, swamp cooler on wheels, fans, tiles, and a misting system. If you dip the bottles in water before giving them to the rabbits, they are more affective. Have an designated "cool zone", like a place in the house, for nest box babies to avoid loosing them from heat.