Sony Xperia Z2 is one of the most stylish looking phones with an impressive performance and great features. But it is not a perfect phone, and has its share of issues, one of them being the overheating problem, particularly when shooting videos in 4k. For one, it is better to not shoot 4K videos for an extended duration. This is because shooting in super high quailty 4K resolutation can sap the battery life and demand high performance from the processor and RAM.
If you really want to shoot 4k resolution videos, you should install an SD card with maximum storage and shoot 4k videos in small bursts, which should about a few minutes at a time. Xperia Z2 can work with capacity cards up to 128 GB. Also, Sony has come up with a fix to improve overheating issue. You can check this by going to the settings of your phone – About Phone – Software Updates- System Updates.