Thermoelectric was my first thought, since it can heat or cool, to maintain a set point, warm food, or chill beverages, as implemented in some fancy lunch boxes. I didn’t know if the same applies at this scale, but I’m assuming this unit uses a compressor.
Hmm, I usually see Nemesis pitted against Insurrection. Although I enjoyed both (thanks to lowered expectations) the latter tagged the cake as feeling like a not particularly well produced, but extra-long episode.
V and VI are the ones I get mixed up, but I remember being more disappointed in Undiscovered Country than Final Frontier. Perhaps it was just compounding disappointment at that point…