also it wouldnt be a "short" anyway. A short is when you send power to ground with no resistance like a transistor, led, or resistor in between.
What you would be doing (if it actually is a problem in your case) is overloading your power supply. Which heats it up. And then you release all the magic blue smoke and then you buy a new arduino. or i guess you could replace the power thingy you burnt up.
caveat. im a complete newb too so dont take my word for anything. read up on it.