I make sure my ferrets always have access to plenty of fresh water in their hutches and I also make a point of taking a bottle of fresh water with me if we?re ferreting in hot weather.
In conditions like this your ferrets deserve a drink and they will work all the better for it ? just think about how dehydrated and lethargic you get when the temperature rises and you?re not able to get a cooling drink!
Commonsense should tell you that on a hot, sunny, day you should place the ferret box in the shade and that you keep a close eye on how they?re working.
If, for instance, a ferret keeps turning towards a nearby puddle or stream then it?s obviously telling you something!