do you use a/c in the cool/cold weather?....

as the title states, is there any advantage to having a/c on at any time other than summer?



i live in a very cold winter climate and have always just run hot air in the winter



tonight for the first time it was cool outside (10 celcius) and so i had to turn the heat on for the first time since last winter and the a/c button was on the whole time... it got me thinking, is there an advantage/disadvantage to running a/c while using heat in the fall or winter? will it help/hurt with windows fogging?



thanks