Damn it's cold...

I had a great first-hand demonstration of the lapse rate last night.
Around 11 p.m. I took off for a quick in and out to Shenandoah. Colder air had pushed into the area during the day, promising snow and a wintery mix today but reasonably clear skies prevailed for the quick flight. It was cold on the surface and obviously significantly chillier at my cruising altitude.
Since the tower controllers had packed up and gone for the day, I raised Potomac Approach on the phone to get my clearance and release. Within minutes I was off in moonless and frigid skies.
The Seminole has a very rudimentary heating system, which operates pretty much either full on or off. Still, it gets the job done. A little care is however required in operating it. The POH notes that if the heater, which burns fuel to produce heat, is used during ground operations, the fan should be activated for a full two minutes after shutting the heat off in order to cool the system. In the air, all it takes is to let air cycle through for 15 seconds. Failing to do so will result in a heater overheat light appearing on the annunciator panel and the system going offline until a reset switch is accessed in the nose section. The reason, obviously, is to physically have someone go in there and check for any damage.
The aircraft in question last night had been recently used on a checkride with a somewhat spaced-out examiner who cranked up the heat during the flight and failed to follow proper cooling procedures.
As a result, I inherited a flying ice box.
With temperatures around -15C at 8,000 ft, the cabin got fairly chilly in a hurry, even though I'd planned ahead and flew all bundled up in my coat. It wouldn't have been so bad, however, if I'd properly shut the door, which came slightly open after take-off, allowing a stream of accelerated frigid air inside. I elected to fly the plane and fix the problem on the ground in Shenandoah, which made the return flight just a little more bearable.
In spite of the cold it was a pleasant flight, conducted from the right seat, which took some getting used to, especially in the dark. For the first time, I flew over mountains at night and realized just how featureless terrain is in the darkness.
On the way back, around 1 a.m., a lonely approach control showed a friendly side generally foreign to many of his day shift colleagues, again underlining how different night flying is.
I also thought of the freight dogs up there at that time of night. Wouldn't mind giving that a try some day.