If it's a fairy new machine, there might be a diagnosis routine you could run. That might give you a code leading to the problem. Also hidden somewhere in the machine is a paper intended for a service person to help troubleshoot service.
Clothes irons draw a lot of current. If you're experiencing this hot plug at only the one outlet, the outlet is bad. Chances are that the contacts in that outlet are not squeezing as tight around the iron plug prongs. If that's the case some arcing is taking place, causing the heat you're feeling on the plug. Fix? just replace that outlet with a NEW ONE.
That is very dangerous. A potential fire hazard. An appliance that heats should be on as short a cord as possible. Two factors. The longer the cord the the more chance of a hot cord. One of the cords might be too small a gauge, causing too much resistance resulting in hot wire.