How to Take Care of an Overheating Power Adapter
What to do, what to do?
I love my laptop. Sometimes I think I use it more than I should, such as when try to move my charger cable only to find that my adapter is piping hot!
Why do adapters get hot? Well, they have to convert the Alternating Current (vibrating electrons) from your wall socket into the Direct Current (moving electrons) that electronic components need to function. Basically, it converts one form of energy into another, just as a car engine converts fossil fuel into mechanical push, and just like a car engine, the process isn't 100% efficient and some (or a lot) of the source energy is lost as heat during the process. This is generally why old, beat up electronics might consume more energy than when they where new.
What to do? Well, in all honesty, if the adapter is getting too hot, chances are you should replace it.
What if I can't or don't want to buy a new adapter? If possible, you should firstly try to see if the adapter is still producing the voltage it should, if it's too high or too low it might cause issues. For that you need a voltmeter, if you have a voltmeter you probably already know how to proceed with that... if you don't have a voltmeter you're probably better off buying a new adapter, they should cost about the same.
Anyway, once you've decided to NOT buy a new adapter (and dismissed plan A):
Make sure it is well ventilated. The plastic needs air to flow around it in order to not overheat. Though it could work while being super-hot, it could be super-ruined once it gets hot enough to damage the materials in it. Simply putting it on a hard surface and AWAY from any cloth should be enough. Also keep it away from you or anything else that it warmer than room-temperature (this includes pets, which could also chew on cables)
Once it's well ventilated there shouldn't be much issues. It really isn't a big deal. A common error is trying to disconnect a laptop charger in order to give the charger some time to "cool", this actually does the opposite, since it'll just get hotter than before once you connect it again and your laptop (or other electronics) sucks up its operating energy PLUS charges the battery at the same time. The temperature won't just go up and up if you leave it in, this is because the hotter it gets, the easier it is for air to absorb the heat energy, which will lead to a point of balance that depends on a bunch of stuff that's probably enough to fill another article. NOTE: I;d especially want to keep it away from anything flammable, just in case it gets TOO hot.
Expert mode: attach a heat sink to it. This will make it easier for the air to absorb the lost energy (heat) and keep the temperature down. A quick search on Amazon or Ebay should bring up some results. A few small VGA heat sinks should do the trick. Using a larger heat sink would mean finding out which face of the adapter hold the inner heat sink which might mean opening it up (or just put it on the hotter face) (NOTE: using a larger heat sink might require sanding one of the surfaces, if you don't already know the risks involved in doing this, don't even try it... but you're probably too cool to pay attention to me, right?).
Anyway, if you have any comments or questions just leave them here, I'd be more than glad to polish up this article a bit in order to cover your specific concerns (because you are so important to me).
Good luck!