When wires get hot the insulation around the wire also begins to melt which then leaves the bare wires exposed.
Those bare wires then cause a short between them and can start a fire.
Also the wire itself heating up when melting the insulation can start an electrical fire too.
Normally copper household wires such as Romex inside your walls should not get hot and if they do then the wire is overloaded and a fire could start.
Also normally while extension cords and other smaller cords may get warm the wire inside your walls really should never get warm or there's likely a problem of overloading.
The wires in your wall should carry more current without heating up than cords and extension cords.
The electrical current through the wires itself causes the home wiring to heat up.
This is because as the electrons flow they come across the resistive forces of the medium's material, releasing energy that is expended in the form of heat energy.
Once a wire gets hot, the heat can travel along the wire until it gets to an electrical connection, such as a plug in a wall socket.
Once the connections in the plug get too hot, they melt and expose bare wires.
These ultimately cause a short circuit, which produces more heat and melts the plug connection.
It's OK for wires to get warm but it's not OK for wires to get hot.
If the wire gets hot where you cannot hold it in your hand for more than a few minutes then the wire is overloaded and it could start a fire.
Wires carrying current can get hot if they are overloaded which means you're using too much electricity and the wire is not rated for the amount of electricity amperage that is flowing through the wire.
However it's normal for the wire to get slightly warm as the current flows through the wire but it should never be hot.
If your outlet is hot then there's either a loose connection between the wires of the outlet or the outlet is loose and not holding the plug in the outlet.
Outlets should never get hot and if they do get hot they can start a fire.
The outlet needs changed out with a new one and the wires checked if the outlet is hot.
A hot plug can cause a fire.
A plug can get somewhat warm such as with a space heater but it should not be very hot and only warm to the touch.
If the plug is hot or the outlet is hot then the appliances or plug should be unplugged to prevent a fire.
It's not normal for plugs or outlets to get hot although they can get a bit warm.
When a plug or outlet is getting hot it's likely because of a loose connection or a bad outlet.
The outlet may not be holding the plug in tight enough which leads to resistance in the circuit which then heats up the outlet and plug.
Also if you smell a burning smell or the outlet is actually hot or you smell a fishy smell then you should shut the breaker off those those outlets that are hot.
Then contact an electrician or if you can do the work yourself get a new plug and fix the issue.
Electrical fires can happen at anytime and can occur while you're asleep as well.