Chickens are pretty tough but very hot weather can be dangerous. Chickens can suffer heat exhaustion, dehydration and even die from a very hot day. Any days over 35 Celsius (95F) can put chickens at risk.
Here are some tips on how to manage chickens in hot weather.
1. Shade and soil
On hot days, chickens will find the shadiest spot and dig down into the soil. This is because the soil gets cooler and damper as you go deeper. Letting your chooks into the shadiest part of your yard (that is still safe from predators) where they can burrow into the soil will help them get through the day.

If you have a long dry spell (Australia has droughts that last years), it may be the soil is very dry even at depth. Hosing the area down before giving your chickens access can help.
2. Water, ice and cooling treats
Chickens are dumb. Ok that’s a little unfair but they do some pretty dumb things, like not drinking water on hot days if the water is too warm. Regularly changing the water throughout the day so its nice and cool will encourage your chooks to keep hydrated. If you can’t be home, freezing a large block of ice (in an ice cream container or similar) and putting this is their water will help keep it cooler for longer.
It also helps to provide a number of different water sources that will be in the shade in different parts of the day.
Providing cool treats like watermelon straight from the fridge can also help.

3. A misting system
A misting system is especially helpful if you can’t be home for the day. When I got mine, I set it up in the shady part of the coop thinking the chooks would stand in the shade and enjoy the cooling mist, appreciating how loved and cared for they were. But no, as previously mentioned chickens are dumb. They were terrified of the mist and huddled as far from the cooling system as space would allow i.e. in the direct sun. Eventually I figured out to move the misting system to the sunny side so at least the chickens would stand terrified in the shade.
It’s good to have the misting system on a timer so its starts when the day warms up, so you are not just running the tap all day. The little misters can block quite easily too, so a regular check is always good.
Here is a YouTube video on how to set up a misting system Installing a Misting System for Chickens.
4. Bring them inside
Chickens will hold their wings away from their sides to help cool down, as well as pant. If they are sitting still and panting and looking visibly distressed it may be time to bring them inside. I have used a water bath to cool down a struggling chicken (see picture below). They are usually surprisingly compliant, standing quietly in the tub, and on one occasion one girl just sat happily down in the water.

You can also put them in a pet carrier and bring them into an air conditioned room. I had a lovely afternoon watching a movie in the air con with a couple of chooks in their carriers enjoying the serenity.

Conclusion
Its possible to get your chickens through a hot day with a little bit of foresight. If you can manage to be at home to tend to them, this is best, but if you can’t be home, hopefully the above tips provide some options to get your flock safely through the day.