Samsung has packed a bunch of upgrades into the new Galaxy Z Fold 8 Ultra, but the one noticeable absence is the lack of any sort of active cooling system. The Galaxy S26 Ultra has a built-in vapor chamber to prevent heat build-up, and similar features have existed in non-folding flagships for over a decade.
The question isn't why hasn't Samsung added a vapor chamber to its foldables yet, it's whether that actually matters. The Galaxy Z Fold 8 Ultra has the same super-powered Snapdragon 8 Elite Gen 5 for Galaxy chip as the S26 Ultra, and I was curious how much heat would actually build up in both phones — and more importantly, where it ends up.
