Do Metal Roofs Turn a Bird House into an Oven?

Birdhouses can be a great way to help out nesting birds in your area, but they can be a bit intensive to make. As part of a 500 birdhouse marathon, [Of Human and Nature] decided to test whether a metal roof would be safe or turn the birdhouse into an oven . Most DIY birdhouses are made of wood to encourage cavity nesting species that would naturally find a hole in a tree to use the house.