With a more powerful processor on the Raspberry Pi 4, this means more excess heat can be expected. The new Broadcom BCM2711 System-on-chip (SoC) has the same packaging as its predecessor, but it is more powerful and will run noticeably hotter than the Raspberry Pi 3 Model B+. To protect your Raspberry Pi 4 from overheating, use heatsinks.
In this guide, learn how and where to attach heat sinks to your Raspberry Pi 4.
After completing this guide, your Raspberry Pi 4 will be much more safer from overheating.