life contingencies

It depends on the thermal conductivity of the mug / glass. An insulated cup is your best bet. Of, course, I like my coffee on ice.

What-no mention of surface area or thickness? If, as you mention in your second post, you will burn your hands on the glass, that implies a higher temperature of the outside of the glass, which in turn implies greater heat loss (due to higher thermal conductivity and/or less insulation due to thinner walls).

Also, mugs, in my experience, are generally closer to the ideal spherical shape to minimize surface to volume ratio, so glasses tend to have more heat-loss surface.

Dick

I am assuming we are to limit ourselves to porcelain/china vs. glassware.

I'm not bitin'.

Bhankiii, for a guy that works at NASA, that seems to be an unusually generalized response ~ sans wit and quip.

Yes, well, last week we all got project coffee cups - stainless steel insides with an insulated blue plastic outside, a non skid rubber base and a close-able spill proof top. Very nice.

If the choices are just a china cup or a glass, I have to go with the cup. Hot coffee in a glass will burn your hands.

Hot tea in a glass will, too, but that is the traditional way of serving tea in Russia. A fancy metal glass-holder saves Russian hot-tea drinkers from burnt fingers. The glass-holder is usually a network affair, so that the thermal path from the glass to the fingers is restricted. I guess you could still burn your tongue, though.

In South America they commonly drink 'mate', which is effectively a very strong tea, although it may also contain alcohol. they drink it form a gourd, which may or may not have a metal base. The gourd protects the fingers from the boiling-hot liquid, but they drink it through a 'bombilla', which is a metal straw with a bulbous filter on the bottom. If they are rich, the bombilla is of silver! I tried a couple of times, but just burn my lips!

Dick

Depends upon the thickness, material and surface area of the mug. Obviously a metal mug with a very large surface area will lose heat much faster.

Well well - how thick is the glass how thick is the mug. What is the mug made of? Do you preheat the mug or glass or do you take it out of the freezer? what is the diameter? Too many variables!