To answer that question, we took our trusty thermometer in hand and ran a series of tests that pitted Apple's latest tablet against the iPad 2 and two popular Android tablets--the and the LTE version of the . Our results are likely to be reassuring to any potential iPad purchasers. Though the new iPad did run hotter than the iPad 2, the difference wasn't great. And in repeated lab tests of the new iPad, we could not replicate the disturbingly high temperatures that some sources have reported. More important, the new iPad was not dramatically warmer than either the Asus Eee Pad Transformer Prime or the Samsung Galaxy Tab 10.1 LTE, even though its battery has a substantially higher milliampere-per-hour (mAh) rating than theirs do (11666mAh for the new iPad, versus 7000mAh for the Galaxy Tab 10.1 and 6930mAh for the Transformer Prime).

Though our tests do not definitively address the question of whether the hotter temperatures pose a risk to the iPad's longevity, they do suggest that any heightened sense of alarm on the part of users and prospective users is unwarranted. Many mobile devices get toasty--and often much hotter than the top temperature of 100 degrees Fahrenheit that we recorded on the new iPad. For instance, a quick in-office test of a three-year-old laptop running basic office tasks registered 108 degrees Fahrenheit; and an on-lap , after running for about 30 minutes, clocked in at 112 degrees.

Using a Raytek Raynger ST-Handheld Infrared Thermometer, we took multiple temperature readings on both the front face and the back of each tablet, measuring the temperature at the tablet's center, at the charging port, and on the back. We took a set of baseline readings (not reproduced in the chart below) when the tablet was turned off; another set of readings when the tablet had been on but idle for 5 to 10 minutes; and a third set when the tablet had been on for 1 hour while continuously playing Vector Unit's graphics processor-intensive Riptide GP game. We kept Wi-Fi on throughout the testing, and the room's ambient temperature was comfortable and controlled. We conducted the series of tests first with each unit plugged in and charging, and then with each unit running solely on battery power.

The test results were consistent with our casual experiences while using these tablets: The Raytek thermometer revealed that each tablet has its own particular hot point, and that in some instances a tablet's front can be just as warm as its back. In addition, we noted that temperatures tended to run higher when tablets were plugged in than when they were running on battery power.