It was a few weeks back...a lot of them were juices I have ordered before and so far I haven't noticed any difference at all. Here is the thread (short one), but you can see the response I recieved at least. http://www.e-cigarette-forum.com/fo...cussion/306113-juices-left-heat-thoughts.html
Really the same answer, heat accelerates the steeping process and thus shortens the shelf life. At two weeks mine looked and tasted normal too but at two months they were ruined.
If you can put a small amount aside as an experiment and wait a few months, I'd be curious to know if it happens to yours.
That Phoenix sun can be pretty brutal. I'm due back there in August and certainly won't be ordering juice. I've had concerns about batteries shipped there in summer as well, but I was quick to retrieve them and a year later so far so good.