In case you missed it, RPi 4 got a new bootloader that helps manage the heat this SBC produces.
If we are being completely honest, this release was from July. The big news is that we now consider this release "stable" based on the release notes and that fact that it is featured as the default bootloader on the NOOBS and Raspbian download page here. Raspberry Pi recommends making this upgrade to your Pi using the rpi-eeprom update package. Check out the whole summary on Hackaday!
It is worth noting that this is still a powerful SBC and depending how you use it, can and will still get hot, but it shouldn't be all the time. For when things really get cooking, SparkFun has some new cases for the Raspberry Pi 4. Not only do they look great, they also provide a solution for managing the heat produced by the Pi, which is not minor -- it's basically winter in Colorado now, and we caught some of our engineers warming their hands while testing our Pi kits on the new board. Additionally, the Fan SHIM provides an active solution for cooling any Raspberry Pi!