Hot and Cold

Why does the temperature of my office vary 20 degrees from one day to the next, regardless of the weather outside? It's actually not even that regular. It's completely random and, of course, I always guess wrong. Today I banked on it being a solid 80 in here as it was yesterday and am subsequently freezing my ass off in this longsleeve T. Sometimes it will be 75 outside and they'll fire up the heaters. Other days it will be cold and rainy and the AC will turn this place into a penguin habitat. Ya just never know. At least if I get pneumonia, I've got a case for workers' comp.