Chickens can usually handle cold better than heat. The two most dangerous times from heat are when they are in there during the day laying eggs and at night when they are roosting. Metal coops can be great as long as you are aware of this and manage it.
I don't know where you are located. That could make a difference in how you set it up. If you are in an area it gets hot and sunny, you might want to try to position it so that it gets protection from the afternoon sun. Maybe on the northeast side of a big tree so you are protected from the Southwest and West sun, something like that. That may not be an option or may not be necessary depending on where you are. That metal can really heat up from sunshine, so shade may be absolutely essential where you are. That just depends on your local conditions.
As others have mentioned, ventilation is very important, both for heat and cold. In the summer use the principle that hot air rises. Have vents at the top of the coop and at the bottom. As the coop heats up, cooler air will come in at the bottom and hot air will go out at the top. You'd be surprised how much difference this makes.
In the winter, you need to get rid of moisture and ammonia. The chickens give off a lot of moisture just from their breathing and their poop gives off moisture and ammonia. Ammonia can damage their respiratory system if it builds up. Since ammonia is lighter than air and will rise and hot air rises and can hold more moisture than cool air, in the winter you want vents up high but don't really want vents down low. The coop stays warmer that way but the big benefit is that you do not create drafts on the roosting chickens. Think wind chill. You do not want the chickens in a draft in cold weather.
Getting proper ventilation in a metal building can be difficult. An easy way in a lot of buildings is to cut out under the overhang and cover that with hardware cloth to keep out predators. Many metal buildings don't have much of an overhang, so you can't keep out rain with vents up there without some extra work and innovation. The other concern is how to attach the hardware cloth so a big raccoon can't just rip it off. There are ways top do this, but I don't know what that building looks like so I can't comment too much on exactly how to manage this.
I'd consider putting the nest boxes on the cooler side of the building, say the North or Northeast.
Metal buildings can be great, but they can present certain challenges. If you can manage those challenges, they can be great. One wall of my coop is metal. It can be managed.
Good luck!!
