What are solutions for heat reduction and increasing the lifespan? - Librem 15 v4

Good day, all,

I have owned a Librem 15 v4 for 2 and a half years. Over time, it has heated up more often than I remember when it was new. I am concerned about this because I feared that excessive heat would damage the CPU. I have read other forum posts and noticed that heat is a problem with Librem laptops, such as this one:

https://forums.puri.sm/t/librem-15v4-first-impressions
“* The fan growls like a disgruntled cat, depending on the workload. This is somewhat unavoidable due to the wimpy CPU struggling to keep up. I was on a conference call and one of my peers asked “Who’s running the vacuum cleaner?” (It doesn’t help that there’s no mic plug, so the mic is so close to the fan.) Hopefully this will improve with lower TDP going forward. Yet another reason to support more cores at lower megahertz. It might also be improved by expansion of the heat spreader, but this is easier said than done, and might entail making more cooling slots in the chassis underside.”

However, I have been trying to find solutions for a while on how to reduce heat usage. I have read that under normal usage, a laptop should not reach above 40 C, but when browsing the web with FireFox or checking e-mail with Thunderbird, it often shoots up to 55-60 C, and sometimes above that. These programs often hog up significant CPU cycles (For example, 100% of the CPU is used by FireFox when browsing the web. I am typing this now from FireFox on a similar-spec desktop computer and only 20% of the CPU is used.).

Furthermore, the fan once turned on at 40 C, but after installing a new operating system (I replaced PureOS with Gnuinos hoping that the lighter footprint would reduce heat problems), it started turning on only at 45 C.

I have tried a number of solutions, including installing tlp and thermald, as well as blowing dust out of the processor with compressed air. I have yet to try the solution I am linking to below because I am currently repairing my laptop:
https://forums.puri.sm/t/how-to-reduce-annoying-fan-noise

Besides the remedies I attempted or linked to, what other suggestions do you have for reducing heat on the Librem 15 v4? Also, how else can I improve the lifespan of my laptop?

Some librem 15 users have found disabling CPU Turbo to keep the fan from turning on while still having adequate performance.