A lot of people complain of Exynos 2100 and SD888 overheating. So lets try to make a "cross devices" average temp. Mine is 36C average 24h measured by CPU monitor app.
Samsung Galaxy S21 Ultra, Global, Exynos 16/512GB model on stock, unbranded, Samsung firmware for CSC code BTU on AUE1 release.
More than happy with the temperature on this phone/firmware. No overt overheating. Does get a bit warm after a couple of hours wireless charging and rises to 37C after 10 minutes shooting video.