So I spent the last few hours wandering around the edges of downtown San Francisco, testing the iPad with AT&T's 3G network. I didn't find anything terribly unusual about either the device or the network performance at my first four stops; it wasn't until I was in the home stretch that things went to Helena Handbasket.
Briefly, my test measures the load time for the home pages of a half-dozen Websites: the New York Times, the Detroit Free Press, Fark.com, Gawker.com, the Daily Mail and (being the loyal employee I am) the eWEEK Labs site. These were generally loading in under half a minute at each of my stops.
For my last round of tests today, I decided to sit on some unused steps of the building across the street from eWEEK's offices at Second and Mission. The sun had come out maybe an hour before, so the steps were warm, but not ridiculously so.
Now, this part of town is known to be a black hole for AT&T service, so I expected that these sites would take longer to load than they had elsewhere in my perambulations. What I didn't expect was that they would take so long to load that the iPad would time out and lock the screen, the device being set to do so after 5 minutes.
So I started loading the Times as the first page of my test, and after 5 minutes it still hadn't finished loading. I noted that and moved on to the Freep. Again, the page took forever to load, but instead of the auto-lock, the screen displayed a warning that the device had become too hot and was shutting itself off for its own protection.
Keep in mind that I'd been sitting in direct sun for 10 to 12 minutes at most, and the official temperature as I'm writing this (about 45 minutes after the warning message) is around 66F. If I had to estimate, I'd say the surface temperature of those steps was no more than 80 to 85F; I was a little warm in my hunting jacket, but nothing like Las Vegas hot.
It looks like I won't be taking an iPad to the beach or the park this summer.
Here's what an overheated iPad displays: