Just noticed this warning screen on my 3G the other day. Happened once, and lasted for maybe 30 seconds. It was a hot day, the phone was mounted in a windshield mount in direct sunlight, was charging and using the GPS. I'm not that surprised.

Just to clarify: nowhere in this post or the linked does it say Apple is "admitting" anything. The issue has been raised in the past, however, only recently (june 25th/09) has Apple updated the article "HT2101" as a result of the high rate of complaints about the iPhone heat issues.

I remember seeing this issue appear with the iPhone 3G, but it seems to be far more prevalent with the new 3GS. I haven't noticed much of a heat difference with mine, but I currently have it in a Vaja case so I don't think I'd really be able to feel a heat increase unless it was on the screen.

@BC
the comments in that mac world article are too funny!

I got the white 16gb 3gs and it actually stays much cooler while charging and browsing the net than my 3g used to.

Ya this is not new, Apple had many issues with all iPods/iPhones. Currently the white 3GS (Again) are having heating damage, check here... http://www.iphoneincanada.ca/forums/showthread....

apparently this issue is not new, and does not mean Apple is "admitting" a heat problem specifically with the 3GS

see :
http://www.macworld.com/article/141508/2009/07/...