iOS 9.3 is coming in the Spring and will introduce Night Shift as well as a number of other new features.
Consumer Reports Finds New iPad Gets Warm, Can't Charge Under Heavy Loads
The piece did note that the iPad felt "very warm but not especially uncomfortable if held for a brief period" during the testing process. In a statement earlier today, Apple said that the iPad was "operating well within our thermal specifications."
We ran our 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. (Apple recommends not using the iPad in environments over 95 degrees.)Potentially more interesting is Consumer Reports' note that their new iPad didn't charge at all when the game was running. In fact, the battery continued to drain slightly under the extremely heavy CPU and GPU load from Infinity Blade II.
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.
It seems that under extremely heavy processor usage, the iPad is unable to draw sufficient power from its USB connection to both power the device and charge the battery simultaneously.