Heating issue with Sony Xperia Z3+ was really worst, and Sony accepted the fact mentioning to release an update to fix the issue. Sony kept its word and released an update for Xperia Z3+. The update weighs around 70 MB and has 28.0.A.7.24 as build number. You should receive the notification about the system update, and you can also check it manually or update via PC companion app from computer.
As we said earlier that Snapdragon 810 is well known for heating issue, and the update will not do magic to reduce heating from the device. In simple word, Update is a compromise with the processor speed and performance to reduce the heat. It will simply limit the system’s performance to keep it cool. Samsung was wise enough to skip snapdragon 810, and choose its own Exynos chipset in case of Galaxy S6.
The update is based on Android 5.0.2 OS, and It could take a few days to reach all the region. Users from some countries may need to wait for little.