I live in S. OK and have not lost any birds to the heat in my aluminum houses. My birds usually fledge before the sweltering heat of summer arrives. Below are several pictures of popular aluminum houses. Wooden Houses Wooden houses have been around for a long time. They pre-date aluminum houses.
Gourds are probably the only martin housing that has been around longer.
There have been many attractive wooden houses made over the years. Some are actually better to look at than to use as martin housing. Let me explain. Many wooden house plans do not allow the compartment to be opened and inspected during nest checks. This is very important.