Of course, you probably walked in wearing a sweater anyway, since it was cold outside.
Sixty-nine seems to me to be a very comfortable temperature. If it is too cold for some they can wear additional clothing.However, if you jack up the temperature in summer a lot of people are going to be sweating like hogs and just almost sick, and they can’t really strip to their underwear in an office. The temperature needs to be kept below 70 year round.