iPhone Duo reviews: foldable runs noticeably hot under load

Reviewers report the iPhone Duo gets warm during FaceTime, camera use and gaming. In a 30-minute gaming test the body hit 46.5°C versus 43.8°C for the iPhone 18 Pro, frame rates were 20% lower and brightness dropped from 300 to 185 nits. Apple says the warmth reflects its thermal design moving heat away from the A20 Pro chip.

• Gaming test: iPhone Duo reached 46.5°C, iPhone 18 Pro hit 43.8°C
• Frame rate 20% lower and brightness drops from 300 to 185 nits
• 3DMark stability of 75.9% versus 79% for the iPhone 18 Pro Max
• Heat gets trapped inside when the device is closed