The good thing about gardening in a field is the sun that shines on the vegetables so they can grow tall and be happy.
The bad thing about gardening in a field is the sun that beats down on the gardener making them wilt and be miserable.
If you are going to be working out in the sun a long time and want to create some shade - here is an easy portable method.
All you need is a huge beach umbrella and a bucket full of dirt or rocks. Open the umbrella and poke the spike end in the bucket and voila..instant, portable shade.
And if it is really hot and you want to have deluxe shade, get a box fan and run the extension cord out to where you are working so the fan blows on you while you are under the umbrella weeding.