As for summer heat - our coop is 3 sided, like SockPuppet's. You can see a picture here:
https://www.backyardchickens.com/web/viewblog.php?id=19548
We built it under trees to keep it cooler and it's hard to tell from the photos, but there is also ventilation at the top of the three walls.
If you have sand in their run, you can wet in down for them in the mornings - that would make a nice cool place for them to lay.
I heard that the reason scratch is not good for the chickens during the summer is that the corn/carbs tend to be fattening and a fat chicken will be hotter. That's why it's so good for them in the winter - it helps them to put on body fat for warmth.
https://www.backyardchickens.com/web/viewblog.php?id=19548
We built it under trees to keep it cooler and it's hard to tell from the photos, but there is also ventilation at the top of the three walls.
If you have sand in their run, you can wet in down for them in the mornings - that would make a nice cool place for them to lay.
I heard that the reason scratch is not good for the chickens during the summer is that the corn/carbs tend to be fattening and a fat chicken will be hotter. That's why it's so good for them in the winter - it helps them to put on body fat for warmth.