Not only does Qualcomm's Snapdragon 888 have a reputation for being extremely fast, but also for being very hot. Asus has already demonstrated that it can cool its smartphones excellently in the past, but the new chip poses a challenge even for the gaming king.
https://www.notebookcheck.net/ROG-Phone-5-Asus-is-only-partially-able-to-tame-the-Snapdragon-888.532693.0.html
Considering that the Xiaomi Mi 11 and the OnePlus 9 Pro also suffers from heat problem because of the SD 888 chipset, I might hold off my decision to upgrade my current phone to any latest flagship. I want to see if this heat problem also happens in the Sony Xperia 1 Mk3 and 5 Mk3 since Sony deeply value battery longevity.
I've never seen a model allow its middle frame to go that hot, it's amusing what hard(twisted) choices SD888 is forcing onto manufacturers. Looks like it's simply not fit to run full speed on a chassis of this size, physics defined.
My MI MIX 2S did heat up about as much (48° battery, 90° CPU, 10W charger plugged in) when I was playing Genshin Impact on Medium-high settings and 60 fps. I was surprised by the sustained performance Snapdragon 845 gave me.
So, the phone frame and body became warm during heavy use...? That's exactly what it's SUPPOSED to do! The more heat that can be radiated out into the frame and body, the cooler the SoC runs and the longer max performance can be sustained.
The 888 is looking more and more like a repeat of the 820, which resulted in a bad year for smartphones since that was the only real option at the time, and I suspect played a role in MediaTek's gain on Qualcomm. At least this time around there are lots of other good choices, but it seems irrelevant since most flagships were designed for the 888 before realizing the issue. I wonder if this is going to cause more of them to switch to something else in the future, as the OEMs are (or should be) losing trust in Qualcomm's ability to reliably offer performance at reasonable thermal limits.