Temperature Analysis With An Infrared Camera
Tablets and smartphones are touch-based devices, which means you're going to have a lot of physical contact with them. If you're doing a lot of gaming on an iPad 3 with its brightness cranked up, the device can get quite warm, making it uncomfortable to hold. In comparison, we couldn't come up with any situation where the Transformer Prime gets that hot. To demonstrate, we took some thermal pictures, visible below.
After 10 minutes of idle time, during which the Transformer Prime was allowed to receive notifications, the surface temperature only hits ~84/85o F. Notice the red triangular flag in the focus box; this tags the hottest spot, which happens to be where the Tegra 3 chip is located. While the aluminum body negatively affects GPS reception, it does a great job of distributing the heat generated by Nvidia's third-gen SoC.
After 10 minutes of browsing, the temperature rises a little in certain areas, but the overall difference is negligible.
Ten minutes of gaming sees temperatures increase more noticeably, as we'd expect. Still, Asus' Transformer Prime remains much cooler than the iPad 3, which exceeded 95oF in our recent review. Even after playing Riptide GP for 10 minutes, the Transformer Prime's surface temperature only approaches 90o F.
Moderate temperatures mean you shouldn't experience any heat-related discomfort. The ambient temperature during testing was 76oF, and we recorded skin temperature at around 92o F.