I just thought I'd note that older fridges didn't have that Yoder loop.
Older fridges had an electric mullion heater under the metal mullion to
heat the mullion and keep condensation from forming on it. And, the
manufacturer would put a switch in to turn that mullion heater off if it
wasn't necessary cuz low humidity in the house would prevent
Problem is, they called that mullion switch the "Energy Saver Switch"
and people would invariably turn that switch to the ON position thinking
that it needed to be in that position to save energy. In fact, the
opposite was true. Turning that switch on turned the mullion heaters
on, and in a lot of cases wasted energy.
Also, another very likely cause of a hot yoder loop is that the OP might
have just put a lot of stuff in his fridge; like a case of 24 warm beer.
The more warm stuff you put in the fridge, the more heat has to come
out of the condensor, and the hotter that condensor coil (and hence
yoder loop) will get. Once the beer gets cold, the temperature of that
mullion should return to normal.
You can still buy those electric mullion heaters, but nowadays most
people use them to warm their home made wine or beer to accelerate the