To convert 50 C is 122 F. Pretty hot.
If you check around I think you'll find that chickens live and breed in Dubai, including free range chickens. They are probably certain breeds or strains that can handle that kind of weather but chickens are kept there. From a quick Google search, there was a rule against keeping chickens when the bird flu scare hit, I don't know if it is still in place.
I don't know what you backyard looks like, some can be a lot cooler than others. If you have vegetation for them to get under and such, especially if you irrigate, it may not be too bad. If it is barren and dry, you could have problems.
How do people without air conditioning survive those temperatures? They have for thousands of years. I'm sure you have certain construction techniques and ways to live that manage that. Think about how people manage, you may get some clues as to how to manage your chickens. In any case it will involve shade and water.
People in heat here use some tricks to help their chickens, though few see your type of temperatures. Some are very short-term, like feeding them cold or frozen treats. One method that provides long term relief is a swamp cooler. You constantly mist water in front of a fan, that will cool things off a lot.
A few years back when my temperatures were around 45 C I kept certain areas of the ground (in shade) damp, that really helped. I use white bowls in the shade in the summer for water to help keep the water a bit cooler. Some chickens would stand in the water to help cool off. I don't know what your backyard looks like, how much you are willing to spend, or what it will take for your chickens to manage.
Will they lay in those temperatures? Probably but expect egg production to be cut way back. Mine continued to lay in those 45 C temperatures but it wasn't much, production really dropped. That brings up another point, the nests. If you provide a nest for them to lay in and they actually use it, avoid making the nest an oven. Keep it in the shade and have plenty of ventilation up high for hot air to escape. You may find they prefer a nest in a cool spot on the ground somewhere.
You live in a brutal climate, yet people and chickens have lived and thrived there for thousands of years. But with modern conditions things have changed some. For your chickens to survive and do well, you need to give them the right conditions. It can be a challenge. Good luck and welcome to the forum.
