Do you have a little brush so that you can help groom them with their moult?#
Do you have any Ice Pods? If not you could fill water bottles and put them in the freezer. Then when its hot you can get them out and place in the run/hutch/shed.
Or else a cool tile they can sit on.
Lots of shade from the sun and plenty of fresh water are obviously important.
Ventilation as well depending on what their accommodation is like.