Q: power adapter very hot

    Reset SMC.  https://support.apple.com/en-us/HT201295

    Choose the method for: “On Mac notebooks with non-removable battery”.

  If this does not help, contact Apple.

  Genius Bar reservation:

  http://www.apple.com/retail/geniusbar/

If you supplied the model / year of your Macbook Pro it would be helpful.

If you have a concern about temperature and cooling on the Mac notebooks, you may find the information outlined in the following articles helpful:

Mac notebooks: Operating temperature - Apple Support

Learn about the fans in your Mac - Apple Support

For a definitive answer, I suggest that you take the MBP and the electrical connectors to an Apple store Genius Bar.  The evaluation will be free.

Also if you have a 13" Macbook Pro and are using a 65 watt power supply, the 85 watt power supply will also work and it runs a little cooler.

Find the right power adapter for your Macbook Pro: Find the right power adapter for your Macbook Pro

Kim

How hot is hot?

have you looked at the connections at the MBP?  Is there any dirt and debris in either connection?  Any signs of discoloration?

The pins in the charger connection are spring loaded.  Do they move freely?

If available, try another charger.

Ciao.