how can I read a book in sunny Arizona

No iPad is going to work well in bright sunlight unless you wear a large sun hat on your head or umbrella to shade the ipad from the sun.

In addition, the bright sunlight will heat up the iPad’s glass enough to raise the temperature of the iPad to the point that it will get hot enough to shut down.

No tablet computer works well in direct bright sunlight.

By a Kindle or Nook e-reader for reading outside in bright sunlight OR keep your iPad shaded from direct sunlight.

Good Luck to You!

I've dealt with the same problem; I used to use the Kindle app on my iPad. Unfortunately the best solution I've found is to buy a Kindle e-reader. They work perfectly in bright light: Amazon.com: Kindle E-readers: Amazon Devices & Accessories

Any LED/LCD screen is poor in very bright incident light. Paper white displays work infinitely better for text in bright light. Their battery life is better since they only use power to change the display, not to keep it displayed.

That true -- battery life is outstanding and I think they are a bit easier on the eyes even when reading inside.