One thing I haven't heard any one discuss as a variable is the angle of the Sun light you experience. I know that here in the deep South we can get a lot more solar gain due to the high angle of the Sun. I have a decking material that grows nearly 2 1/2" on a 20' run in the hot Sun. It was a product developed near Canada where they had never experienced that much linear growth in direct Sun light. The deck was 63' long and the expansion was so great it would push some of the bords off the joist and then when it contracted they were not supported. We had to replace the deck boards.

Charles,
IMO the angle of incident (sun angle) can be overlooked because it is variable. The important idea is to keep the sunlight from directly striking the container side (root zone) and overheating the soil and roots.

<edit> added 8/19/13
This Kansas State Thesis has several pictures descriptions and tables of test procedures and results regarding solar radiation and heat gain on containers.
 

Charles, your right about the angles and I think for me anyway the higher the angle the better as it's the lower angled light striking the black sides of the pots that's the problem. This year I moved my biggest pots off the raised back patio ( 2 - 2 1/2 feet off the ground) so they sat directly on the ground. In theory this would expose them to less direct sun on the black sides of the pots. As the top is almost completely protected by the fig plant I thought it was more important to protect the sides. As August is coming I should see if it was the right decision. I thought I'd know by now but we are experiencing very odd weather this year.

So would this decking material expand the same way say a wood that expanded 1 percent with instead off perpendicular to the grain? So a 63 foot deck was pushing along the length of the material over 7 1/2 inches on a deck of 60+ feet. Glad I was in charge of that material decision or the rep for that matter.

Yep right at that 7" or so. They had this very elaborate formula that was used to compute the linear growth with temps but never took into account the solar gain the material would experience. You could fry eggs on this stuff. The boards were twenty feet long and that added to the problem. For most people whose decks were less than twenty feet they never knew there was a problem. I'll have to take the blame on the material choice but I could only go by the manufacturers specifications. The rep on the other hand was happy to replace the material after a few discussions and after he came and looked the the deck. Didn't hurt that he was a friend of mine!

I built my ex a really nice 3700 sq ft timberframe and I used 31 species of hard wood. I learned a lot about the expansion of woods during the first two years. I used every species of oak that grows in Va to make the floor boards on the first floor and came to understand why they don't mix woods very often. A red oak floor is just so much more stable then a mixed oak floor.

What was this stuff?
Great that they replaced the material but I bet you still ate the labor, etc.

I've recently taken steps to reduce soil temperature within my containers. I have to say this thread was very informative.

My question: How long would it take to break summer dormancy?
And at what temperature is optimal for roots? Below 30 degrees Celsius according to that study, but is that true for figs?