I usually freeze small water bottles (like Evian) and then wrap them in a towel. You have to be careful with the ice packs as I believe the contents can be toxic if they chew it?
You can also get 'Chin-Chillers' from Pets and Home, which are like cold marble tiles they can sit on!
A wet towel across the front of the hutch also helps, as the breeze blows through and cools the air
Sophie
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