Nearly 60 degrees on Thanksgiving day and down in the teens on the Sunday after. This is exactly the kind of week when HVAC services throughout the Midwest are tested. In fact, there are times in the same month in some parts of the country where heating and cooling services can run in the same week. Even when you swear, for instance, that you are not going to turn the furnace on in October, for example, it is difficult to stick to this idea when the temperatures dip below freezing for two days in a row. Likewise, you may be…