You'll be fine. Unless there is a fabrication fault, hardware is extremely durable. A good computer case and fans keep temperatures at max 60° celsius, absolutely no need to worry. Of course the fans will get louder, that's their job.
You have to keep in mind, when you google a nose itch, online advice tells you that you have cancer. Same thing with computer stuff.
If your CPU dies, it certainly won't be because you ran it on 100% for a couple of days.