Silver fox are densely furred and can't take alot of heat. When our shed hit 83 we ended up moving ours into our garage, which was climate controlled. Heat was the one thing we didn't anticipate with these rabbits. We thought we had a handle on it before we got them. We insulated our shed, installed attic vents, added a portable AC, etc. Still, the portable AC just drew in more heat from the outside and attic, so the cooling was minimal. Once the temps hit 80 inside, we started adding frozen water bottles, and running fans. That worked up to about 85. But then we had a forecast week of mid to high 90s and decided to move them to the house. This was mid June. It is now October and will be moving them back in a few weeks. Next spring I'll install a window AC, which will solve the negative pressure issues of a portable unit and should be able to keep up with the summer heat.