I have a Mid-2011 MacBook Air (13"). Recently, the 45 watt MagSafe Adapter grew extremely hot (painful to touch) and smelled slightly singed while I was using the machine and plugged into the wall. It appears to still work.
I am using the extender cord, not the duck-head plug, and I live in the United States.
What is a normal high temperature for the MagSafe to reach? At what point do I visit my friendly local Genius Bar?