Henry, I really appreciate your responding to my question and you have helped. I have been doing some research on the use of ridge vents (a ceiling fan is already in place) and wondering if that would help to aleviate the problem. I am not so sure that the air is being circulated properly at the roof top, but I did not know if this would contribute to the extreme temp. variations within the rooms. It appears to me that the top floor was originally designed to be a very large attic rather than two large bedrooms and a bath. I will do some research on altering the roof vents. In any case, thank you very much for your assistance. I'm sure I will be asking more questions in the future as this is our first home purchase so I appreciate your patience.