I am moving into a temporary house without heat because it's over 100 years old. I bought 2 heaters for upstairs and downstairs. They are the aluminum ones at Costco that is a Presto Heat Dish. I have read all I can and researched. It is aluminum disc and electric. Has anyone heard of any problems with these for birds? No tephlon coatings, no fuel. If anyone has any insight, I would appriaciate it! Thanks!