Linear regulator heats up at 60 volts
The thermal resistance of your transistors, if you only use a small copper area for the tab, is 104&deg;C/W. If you ask them to dissipate 0.9W you should expect that the die temperature will increase by about 90&deg;C above the ambient temperature. With a large copper area (50mm by 50mm of 2oz copper) you can get the thermal resistance down to 42&deg;C/W, but you would still see a temperature increase of about 30&deg;C.

If you want to use this linear regulator you should look for a transistor in a package that is better able to dissipate heat, such as a TO220 package, and look for a compatible heatsink.