Does the iPhone Duo Run Hot? Here's What Reviews Found
Multiple iPhone Duo reviews covered the device's thermal properties, and reviewer opinions varied. Some found that it was just warm, while others thought it was running too hot at times. Joanna Stern said the back of the device got warm when using FaceTime and taking photos. She had to end a ‌FaceTime‌ call during testing because it got too hot. "Yeah, I'm gonna burn my hand off," she…
Reviews of the iPhone Duo have touched upon its thermal behavior, with opinions differing. Some users found the device warm, while others believed it ran too hot at times. Joanna Stern noted that the back of the iPhone Duo got warm during FaceTime calls and photo-taking sessions, even forcing her to terminate a call due to excessive heat.
Apple explained that the warmth indicated the phone's thermal design efficiently moving heat away from the chip to maintain performance. However, Stern found the phone to feel unusually hot. The iPhone Duo shares a similar custom vapor chamber setup and A20 Pro chip with the iPhone 18 Pro, but its vapor chamber is thinner. Apple incorporated a flexible graphite pipe in the hinge to transfer heat between the two halves, increasing the surface area for heat dissipation.
The Verge mentioned that the iPhone Duo heats up when using the camera for extended periods, especially when both displays are active for features like Duo Preview. The phone heats up considerably enough to cause noticeable lag. The site also reported that third-party apps, particularly video apps and Google apps, cause the iPhone Duo to get hot.
PetaPixel's review unit became warm during gaming, photo editing, and any processor-intensive tasks, feeling the heat on the right side. Mrwhosetheboss conducted a 20-minute stress test, finding the iPhone Duo trapping heat inside when closed and performing below the iPhone 18 Pro Max. When opened, the iPhone Duo's high-resolution display also impacted performance.
Mrwhosetheboss focused more on performance than heat and stated that the difference between the iPhone Duo and iPhone 18 Pro Max isn't massively noticeable in everyday use. HTX Studio performed a 30-minute gaming test, revealing that the iPhone Duo registered 46.5°C, while the iPhone 18 Pro models achieved 43.8°C and 43.2°C, respectively.
The iPhone Duo experienced a 20% reduction in frame rate and a drop in brightness from 300 nits to 185 nits. 9to5Mac observed that the iPhone Duo runs a bit hotter than the iPhone 18 Pro but not enough to affect performance. Tom's Guide carried out a benchmark heat test, finding that the iPhone Duo evenly distributed heat across its body but was a few degrees hotter than the Galaxy Z Fold8.
The iPhone Duo achieved a 75.9% stability score in the 3DMark stress test, compared to 79% for the iPhone 18 Pro Max and 72% for the Z Fold8. Gizmodo didn't consider heat an issue, stating that the vapor chamber effectively cools the device to prevent lag or slowdown when apps utilize all CPU and GPU cores. The iPhone Duo launches this Friday, leaving little time to determine if heat will pose a problem for everyday users.
Written by urgent.news from MacRumors's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
