My hanging halogen light has written 150W 25V on the bottom of the bulb holder... I just noticed that. I typically use a halogen bulb labeled 35 W 12V. I would think the 150 W 25V labeling indicates the outside limit of intensity;however... I used a 75W 2 V bulb and the heat caused melting of the gasket/glue mass at the top of the shade.

I just installed another 35W 12V hoalogen bulb and the light works.

What caused the overheating? Am I using a bulb that is safe?

That is the Rating for the socket, I believe the most you can put in Many Fixtures is 60 Watts, Does the fixture have a Maximum Rating Label