There was an article in today's AZ Republic about the Phoenix Zoo's annual Winter in July, accompanied by this picture:

Obviously Pokey isn't the only sulcata enjoying the season's melons.  (Pokey doesn't get to wade through snow/ice to get hers, though.)  Surprisingly, the pictured sulcata seems to have a somewhat 'lumpy' carapace, which is one sign of a poor diet; I would think that the zoo would provide a perfect diet!  Pet tortoises that have been (incorrectly!) fed dog food end up with very pointy sections.  Happy to report that Pokey's shell is nice and rounded.