IAD Death March

When I arrived at IAD, I had 30 minutes to walk (what seemed to be) at least a kilometer to get from gate C15 to D15.
Can anyone tell me why lidat?
I mean, does “shuttle” or “train” mean anything to the Washington Airports Authority? How about AirCon? Because once you crossed the line that separates Terminals C and D, the AirCon disappeared. Yeech.
Thank goodness it was at this ungodly hour otherwise there would be teeming masses of humanity (and humidity) making it worse still!
On the plane now, going to Boston.