Just be sure the sun doesn't hit them at any point during the day or they will surely bake. I would not keep them in an enclosed area without an exhaust fan and a fan blowing across the bins. Keeping them in a shaded garage would be good if it is cooler than the outside temp and add a few box fans that blow across the rack and they should be happy. Just be sure to be very diligent about clean bedding and fresh water as you would any animal.