What Degree

Why are temperature degrees different from heat to air conditioning? In the summer when it is hot out we set the air conditioning to 72 degrees. We freeze. In the winter we set the heat to 72 degrees and we sweat. Isn't 72 still 72 whether it is from heating  or cooling? Is a cool 72 different than a hot 72? All I know is that either way my morning receptionist is not happy.