I flew as a passenger on a KC-135 from Elmendorf to Ramstein. It was the coldest, most miserable flight I’ve ever been on. If you stood up, your head was in 80 degree heat while your feet were in 35 degree cold. Then the urinals started overflowing, so we couldn’t use them anymore. If I ever fly Space A, I’m avoiding the 135.
The back end of Navy EA-3s were the same way. We often flew missions with heavy socks but stripped to the waist.
I flew on a KC-135 in Feb 1993 from Travis AFB, CA, to Misawa AB, Japan. Only because the normal cargo aircraft fleet, the C-141, was grounded with wing cracks.
The first phase of the flight was okay, but then we had to divert to Elmendorf AFB because Misawa was closed by a blizzard. Spent the night there, with two feet of snow on the ground. A bit colder than California.
I and a team of escorts were transporting very high priority cargo (two small boxes), so the next day we bumped a colonel and his staff from the next KC-135 shuttle to Misawa.
Miserable flight, as you said. Canvas jump seats, alternately hot and cold, very loud, bad in-flight box lunches. The seating was at the rear of the aircraft, and passengers had to climb over cargo pallets to get to the head at the front of the aircraft.
That is why those of us who regularly deployed on 135's would arrange with the crew to put our sleeping bags or pads on top of the pallets (preferably up near the air ducts). The only thing on the floor would be a cooler of drinks that could be kept nice and cold down there. ;-)
The heater on the KC-135 is the largest machine in the world that does absolutely nothing. I’d take a C-130 flight over a 135 anytime.