*The passenger accommodations were decorated in the clean, modern design of principal architect Professor Fritz August Breuhaus, and in a major improvement* **over the unheated Graf Zeppelin, passenger areas on Hindenburg were heated**, *using forced-air warmed by water from the cooling systems of the forward engines.*
I bet that journey over the arctic was a wee bit chilly in an unheated airship….
Typical cruising altitude 650 ft or less. Top speed around 80 mph.