How much heat should a metal halide bulb radiate at 3 inches?

I ask this because I have two sunburst 12,000k lamps above my 75 gallon now. Some of you probably saw me raving about it in another post. I was in the break-in stage getting the fish and corals used to the light, so I only had one bulb on. At about 3" the temperature was around 78-80 degrees F.

Today I put in and switched on the new bulb, the temperature of it was incredible. Well beyond 140F. I am assuming its too hot, mainly because the color was way off too, it was crisp clean white and not blue-white at all like my existing lamp. It was also so hot I couldn't touch the reflector or top of my canopy, yet my existing bulb is fine and I can hold my hand between the reflector and the bulb .. not with this new bulb though.

So off it goes being returned for a new, undefective one .. but it leaves me to wonder the above question; how hot should they run? I've looked around online and after an hour of searching haven't found an answer.

What do yours run at?