The earliest designs of the Clipper from the 1930s already boast of the most advanced heat insulation and ventilation systems. In addition to electric lights, Airstreams even came with their own dry-ice air conditioning system.
The current Clipper design uses two aluminum shells with a layer of insulation sandwiched in between. The layer of insulation consists of a 2-inch temperature resistant mattress of aerocore fiberglass that's impervious to flame, vermin, water, and settling. This allows for cool temperatures in the summer, and warmer temperatures in the winter.
Structural member of the trailer body being wired
The central door of the Clipper has a part that can be opened to turn the door into a screen for added ventilation. Instead of nails and screws which might dislodge overtime from excessive road wear, each Clipper is constructed with thousands of rivets. Each rivet alone requires two skilled mechanics to drive into the Clipper's body. One can only imagine how much time and effort was required for the completion of each trailer.
In essence, every square inch of the Airstream Clipper was designed for a functional purpose.