First of all sorry to hear about your loss. Unfortunately this is all too common for all of us when we first start the hobbie. I would have to agree the problem was exaustion and dehydration. He could no longer gape his mouth either to cool off because it went on for too long. You probably missed that stage of his hot behavior. If you ever get inspired again...remember to create a true cooler area...about 70 degrees or just keep the heat around 85...and then let it drop at night, but not below 65...that I feel is too cold for my veiled.hopefully this will be the only time you lost a buddy.