According to a news item posted on the Consumer Reports site by Donna Tapellini, the new Apple iPad can run significantly hotter than the earlier iPad 2 model when running an action game.
Using a thermal imaging camera, Consumer Reports’ researchers recorded temperatures as high as 116 degrees Fahrenheit on the front and rear of the new iPad while playing Infinity Blade II.
The engineers ran the test while the new iPad was propped on the iPad Smart Cover, plugged in, and after it had run Infinity Blade II uninterrupted for about 45 minutes. The device's 4G connection was not turned on, though its Wi-fi link was. The ambient room temperature was about 72 degrees.
They also ran the test with the new iPad unplugged. Then they compared the temperature of the new iPad to that of the iPad 2 using the same consumer experience tests.
When unplugged, the back of the new iPad reached temperatures as high as 113 degrees Fahrenheit. It was only when plugged in that it hit 116 degrees. The hottest areas weren't evenly distributed throughout the iPad's back, but were concentrated near one corner of the display as shown in the images taken from the rear of the device above.
So, when plugged in, the back of the new iPad became as much as 12 degrees hotter than the iPad 2 did in the same tests; while unplugged the difference was 13 degrees.
They also noticed that the new iPad wasn't charging while the game was running and it was plugged in. In fact, the battery continued to drain. It charged normally, however, when not running a game.