More annoyingly, the effect seems to be entirely random - some units are happy in the heat, others will shutdown very quickly. In all cases, the shut down is entirely graceful - a warning screen will pop up with a loud banner screen saying "Temperature. iPad needs to cool down before you can use it."
Reading the discussion board, there seems to be a very wide variety in the temperatures at which the effect is seen - some posters seem to indicate that the shutdown occurs at not much more than room temperature; others at much higher temperatures, if at all.
Some have suggested that the iPad ought to be able to dissipate heat very effectively; after-all its entire back panel is a large block of metal which ought to act as a heat sink. Unfortunately, if the processor is not thermally bonded to the metal, it will do no such thing.
Cynics have observed that Apple have subtly assisted users to NOT use their iPads outside by keeping the brightness of the unit low enough that it cannot easily be viewed in bright sunlight!
While being kept out of the sun is a good thing, (so far) 114,000 users on the iPad on the AT&T network in the United States have discovered that a security flaw in the connectivity implementation has exposed their names and email addresses to a group of hackers.
"So what," most would say. However it would appear that those exposed include White House officials; the chief executives of the New York Times, Dow Jones, Time and Bloomberg; and also members of NASA, the US military and the Dept of Justice.
The leaked data was provided to Gizmodo and according to their report the entire iPad user database was exposed, just waiting for an enterprising hacker to find and collect; the list of 114,000 entries was described as only a sample of the entire dataset obtained by the hackers.
It would seem that little has been done with the data - perhaps it is now regarded as too 'hot' to use (especially in the sun!); there have been no reports of increased spam or other unwanted traffic to the email addresses (although self-reporting is a notoriously poor measure of anything).
So much for the 'perfect' device that Steve Jobs presented to the world those few short months ago. The halo's resistance to gravity seems to be waning and cracks in the ultra-smooth facade are appearing.