Why Does Temperature Matter?
Temperature affects an operating Raspberry Pi in at least two ways.
First: According to the Raspberry Pi documentation, CPU throttling is maximally applied when the processor reaches 85°C, but actually begins at 80°C. Temperatures that high are easily reached or exceeded in ordinary use, such as updating the operating system, running Python scripts, or interacting with a graphical user environment.
Second: Running electronic devices hot can diminish the lifespan of the components – a common rule of thumb is that every 10°C increase in temperature may reduce component lifespan by half. Even though some disagree about the quantities, it is undisputed that excessive heat is harmful for the onboard components of the Raspberry Pi – as well as the microSD card, other peripherals, and nearby equipment.
Heat management was a significant issue for the Raspberry Pi 3, which was found to run as hot as 110°C. By comparison, the Raspberry Pi 4B operates twice as many processing cores at 50% faster clock rates. It also features a gigabit Ethernet adapter and a bus that is capable of handling high-bandwidth video streams, like dual-4K video. All of this processing increases the production of heat and exacerbates the effects of temperature that were seen on the Raspberry Pi 3.