CPU fan never silent on TP L380

[Fekete Zoltán <fekete.zoltan%minux.hu@localhost>]

Hi There,

I've installed NetBSD 10 on my Thinkpad L380 laptop. Runs pretty well, 
all hardware works properly.
The only issue I experience is that the fan is always running on some 
speed. The noise is quite annoying.
Please note, that the CPU usage is not terribly high at the same time, 
between 3-7% mostly.
If Firefox runs, then the rpm sky rockets and gets back really slowly 
after not using it.

I have a linux installation also on the same device. After booting, some 
time later the fan gets completely silent. It speeds up only when 
computation needs arise, aka. compilation. Even running Firefox is 
completely noiseless.

What do you recommend to set/check/install to achieve the same level of 
silence?

Thank you,

FeZ