display – Macbook Pro 2019 overheating with external monitor

Problem

My Macbook overheats insanely.

After investigating a bit, I found out that the correlation is extremely strong with having it plugged in to an external monitor with the Macbook Pro monitor also active.

If I unplug the laptop, or use only the external monitor (i.e. Mac in a ‘clamshell’ mode), the heating stops within a minute.

I managed to use a software (sudo powermetrics --samplers smc |grep -i "CPU die temperature") to measure this:

  • Indoor temperature: 23C
  • CPU heat without external monitor: 55C
  • CPU heat with external monitor + macbook monitor on: 95C (fan turns on)
  • CPU heat with external monitor, macbook closed: 62C

Details of hardware

  • Macbook Pro (16-inch, 2019). 2.3 Ghz 8-Core Intel Core i9, 16 GB 2667 MHz DDR, AMD Radeon Pro 5500M 4GB, Intel UHD Graphics 630 1536 MB
  • macOS BigSur 11.4
  • Monitor: HP E233. 23-inch (1920 x 1080)
  • Cables connecting: UGREEN USB C Hub HDMI USB C Adapter with 4K HDMI, 3 USB 3.0, SD/TF Card Reader (https://www.amazon.de/gp/product/B07RRPS5NT/), and then a standard HDMI-cable

Tried fixes that didn’t work

  • Restart
  • SMC reset
  • Never use two monitors (works)

How could I fix this so I can use two monitors also in the future?