The classic and not-so-original "Nail-cooling"
This Wi-Fi dongle (Netgear A6100) was bought new 8 years ago for €40 and served almost every day. It was connected to the 5GHz network, going up to 180 Mbps, which is quite good for this 15-year-old PC.
Unfortunately 3 days ago, it seemed to have surrendered with successive heatwaves (the 5th since May) and transfer speed started to drop to almost zero while staying connected to the network (Windows was showing everything was okay with the signal to the router, but attempting to reach something resulted to '80s-like transfer speeds with a whopping 4 KB/s). Connecting to the 5GHz network became very random, accepting to connect whenever it want. Shit have a proper life atp.
Unplugging it and let it cooling down generally solves the issue for an hour or two, then you have to start over to cool it down.
But as I need that dongle to do its job, I opened it, tried to locate quickly where the heat comes from, grabbed two nails that were lying in a box, applied a drop of thermal paste and applied the nails on the two major heat sectors (one of the main Realtek chip (after cutting the small part of the USB port metal that was over the chip) and the other on the antenna that was also very hot).
Since I did that it haven't overheat yet, although I'll probably have to find a better solution (fix the nails better), and eventually replace it.
But at least it works now without interruption.