Firefox cpu load?

I ve a thinkpad T450s and the fan started make noise (probably for the used gear, i should replaced it). I therefore started to pay attention to the cpu usage more frequently ( the noise was pretty unbearable) and anytime i start firefox the cpu usage goes very high (especially if a look at a video).
Has anyone seen the same firefox behaviour?

How old is the laptop as this seems to be a typical problem for these as evidenced by Lenovo forum. Here is the link and look at some of the posts especially last one.

Thanks, i ve also seen that it may have some fan problem.
But what i m talking is different… the pc survived to many stressful occasion, like compilation of very big program like (openFOAM) and behave normally. Recently the fan broke, the gear make some noise when rotating. So since i m waiting for the replacement, i try to doing only ligthweigth stuff. Like writing or reading, but sometime i have to start the browser.
If i open firefox one of the cpu goes 100% or 4 to 25% and it seems not normal for a google (or duckduckgo).
I switched to vivaldi, it does not give me this problem.
I m not trying to mispoke of Firefox, i just want to know if someone have the same issue.

I don’t seem to see it on my desktops. But i may not notice too much?

I do not see firefox generally producing more load then chromium based, it could be some settings inside firefox profile, or mor egeneral some settings for GPU or CPU causing that.

thermald TLP is running?
or any other powersaving options?
GPU and driver in use? (not sure if this device is shipped with intel GPU only or also with Nvidia?)