I've read to try a frosted bulb if one thinks their lamp is too hot, but that is not making any sense to me. 40 watts is 40 watts, whether frosted, clear, or spray painted black, and you will get the same heat regardless. The light output may vary, but it is in an enclosed structure, so heat will not vary.
I'm curious if anyone can explain what I'm missing here. But I think a 130v would be the better bet as that would certainly decrease the watts which would decrease the heat.