When I had my parrots they were kept outside in large cage in Florida's summer warm weather, however, when cold weather approached I would install my thermo perch. It was designed to keep the birds feet warm in cold weather. The thermostatic controlled perch radiated warmth in a range of 102 to 107 degrees with low voltage.
I was able to leave it on constantly without worrying about the birds chewing the cord which was outside the cage. And my parrots never got sore feet from using the perch. It was quite a nice invention that saved me from needing to bring the birds inside on cold days.
Have you ever used the thermo perch? Ever had any problems with it?