I've used other Linux distros on my Thinkpad but non had this overheating problem when I using it. I've W10 on my machine too, but it's always cool. I've just installed tlp, and even tp_smapi (even it doesn't include L-series). Has anyone encountered the same problem with a Thinkpad? Any help is greatly appreciated.
You can try the solution I provided here: indicators on wingpanel
However I cannot guarantee it will solve your issue. But we can try to figure it out, what causes the issue.