How is heat management done on Rock Pi S?

How hot does it get during long CPU-intensive tasks? Does it do thermal throttling automatically?
Or, do I need to use ondemand linux cpu governor to utilize thermal throttling?

Thermal throttling is configured by default in Rock Pi S’ device tree:

Rock Pi S DTS
rk3308k thermal zones overrides
rk3308 thermal zones
Linux thermal framework device tree docs

I did not perform long torture tests but run sbc-bench a few times.
Here you can find an example result of unit overclocked to 1.2GHz with default (rk3308k) trip points. At the bottom you can see it throttled when running cpuminer at ~60C.

As a side note: I don’t know if Rock Pi S correctly uses rk3308k thermal zones as I think (not being sure) it uses rk3308 and not rk3308k.
When making Armbian support I changed that in device tree so that it throttles at higher temps.