I have to say Chuck that I don't, Since the vast majority of flying here is done in a smallish temperature range, neither very high nor very low (also due to the fact most people stay below 5000' the vast majority of the time) It has never been an issue, but it is something I will certainly brief my students on, so if they do end up flying in different places, they may have a chance to get it right.
We certainly do teach about the change in mixture due to carb heat, it could be catastrophic if you didn't! if somebody descended from high alt without richening the mixture and with carb heat applied.... Detonation city!!
We generally teach as much as possible about the workings of engines and aircraft, I find it makes a much safer pilot, to be honest every one that learns to fly should be made to strip an engine down and descibe the parts of it and the problems that can arise before they get their licences issued!!