Both my cages are atop a heat/A/c register. When I put them there, (Jack's been over a year and Chino 5 months ago) , I covered it as much for the cold air as the hot, dry air. I figured the ambient air temp was fine in the house without the drafts. Summer and winter I keep it at 70-72 in the day and 65 at night. I put in a register filter, closed the flaps, and have a towel on top that I use for under their bathing dish at bath time.
I sure hope you find the cause of the deaths, and I'm very sorry for your loss.
