Yes, we all know this, but sometimes we forget a basic thing, so here is a friendly reminder - clean your rigs. Dust is your enemy 
In the last few days its very hot in my city, so I thought that higher GPU temperature and fan speed on my rig are normal. But, noise from a CPU fan started annoying me and I decided to clean all fans.
At first, graphics card didnt look very dirty. There was only a little dust on a cooler and I didnt expect any significant improvement. Surprisingly, after cleaning GPU temperature went down over 6 degrees. Also, fan speed is 10% lower.
So, dont be lazy, clean your rigs
In the last few days its very hot in my city, so I thought that higher GPU temperature and fan speed on my rig are normal. But, noise from a CPU fan started annoying me and I decided to clean all fans.
At first, graphics card didnt look very dirty. There was only a little dust on a cooler and I didnt expect any significant improvement. Surprisingly, after cleaning GPU temperature went down over 6 degrees. Also, fan speed is 10% lower.
So, dont be lazy, clean your rigs
Wow, thats a routine cleaning
In my country; there are more dusts, so I have a big blanket spread over the machines
And I still clean 4 times a month.
You also need to keep it cool by getting air conditions or air purifier