The temperature is not dictated directly by the material.
As Astronuc points out - which material you have will determine a heat
generation rate. You also have to know how the material is being cooled -
and the net "resistance" to heat flow.
The material will get as hot as it needs to so that the outflow of heat will
equal the internal heat generation rate.
Thus if you have the material sitting in air - with relatively poor
heat conduction rate to the air - the material will get hotter than if
you immersed it in water - with relatively better heat transfer
Dr. Gregory Greenman