Apple’s first foldable smartphone, the iPhone Duo, has reportedly shown noticeable heating during extended 4K 60fps video recording. Chinese tech reviewer Tim from MediaStorm tested a demonstration unit at Apple’s launch event and said the phone became extremely hot after about three minutes of continuous recording.
According to the reviewer, the area directly below the camera module became particularly hot and was almost uncomfortable to hold, while other sections of the device remained comparatively cooler. Tim suggested that the internal arrangement of the foldable phone could be contributing to the concentrated heat around the camera area.
Although the iPhone Duo includes a vapour chamber for thermal management, the reviewer noted that the limited internal space of a foldable design may make it more difficult to dissipate heat during demanding workloads.
Heating Appears More Noticeable Under Heavy Loads
The reviewer said the phone’s temperature was manageable during regular everyday use. The more significant heating appeared during sustained high-performance activities, particularly continuous video recording at 4K and 60fps.
Tim compared the behaviour with the iPhone 18 Pro series, which also uses Apple’s A20 Pro chip. According to his test, the Pro models delivered more stable thermal performance under similar workloads, partly due to their larger vapour chamber.
Reviewer Reports Flickering on the Outer Display
Tim also reported an issue with the iPhone Duo’s outer display after unfolding the device backwards. He said the screen began flickering after the phone was bent in that direction and claimed that he did not apply additional force while doing so.
Apple customer service reportedly told him that damage caused by bending the device in that manner would not be covered under warranty.
Apple Says Single-Device Testing Has Limitations
In response to questions about the reported issues, Apple customer service reportedly said that testing a single device has limitations. The company suggested that prospective buyers experience the phone themselves at retail stores after its official launch.
Apple also stated that newly set-up devices can require around three to five days to adapt following the initial setup. If a user experiences heating that appears to be related to hardware, the company said the device can be examined by technical support teams or at an Apple retail store.
The iPhone Duo is Apple’s first foldable smartphone and is still in the early stage following its announcement. Wider availability and testing across more retail and consumer units should provide a clearer understanding of its long-term thermal performance and display behaviour.