Do you think that the handles supplied with Boiler Fittings are nasty - just a slice of brass with a tapped hole? When they get hot, you get knurled fingers, too! Here is a way of making handles that are at least a bit cooler!
Decide how big the new handles should be and find six pieces of either brass or copper tube (fairly thick wall), just one third of the handle size in diameter and a piece of solid brass the same size— see the first picture.

Arrange them in a bundle with the solid rod in the centre and silver solder them up to make a solid unit.
Pickle and clean them up and place the rod in the three jaw. Centre and drill tapping size to suit the valve and part off—see the second picture.
After de-burring and painting (which I do by screwing the handle on to a long bolt and dunking it), you have a result as in the final picture.