How hot is the core of Pluto?

Just like any other planets, Pluto changes its temperatures extremely. At its warmest, when it is closest to the sun, Pluto can reach temperatures of minus 369 degrees Fahrenheit (minus 223 degrees Celsius). At its coolest, temperature can minus 387 degrees Fahrenheit (minus 233 degrees Celsius).

Pluto is made up of a rocky core surrounded by ices of various gases. When the distance to Pluto from the sun is at a minimum, temperatures are warm enough for the ices to sublimate directly into gas, creating a thin atmosphere. As Pluto moves away from the sun, the gases re-freeze and the planet's atmosphere disappears from view.

Pluto has potassium beneath the surface which undergoes radioactive decay, the temperature "could" increase enough to support an ocean under the icy shell.

There is no concrete information regarding the temperature of core of Plut

Deep inside Pluto are to be found the more heavier, rocky elements such as silicates. These form the core of Pluto. Pluto's interior is primarily composed of water ice of different phases

Given the large amount of rock and the planet's size, scientists expect that the process of the planet forming and the natural radioactivity of the rock inside will have heated the interior sufficiently to melt the ice and allow it to separate from the rock.

1000 C=1832º F

water turns into vapor at 100 C or 212 F

i would say Pluto core is between between 1 C or 33F and 99C or 210F.