Kramer (Michael Richards) says that the "water went down to 58 degrees", however we saw in the previous scene that the thermometer read 52 degrees.
When Mr. Wilhelmina enters George's office, George turns his newspaper over twice.
When Elaine as to write a description for the catalogue about the Himalayan walking shoes she thinks of a cold winter night in Timbuktu. Timbuktu is not in the Himalayas but in Mali, Africa. Winter temperatures there hardly ever go below 50 degrees Fahrenheit/10 degrees Celcius.
Kramer's industrial-strength hot tub heater plugs into a standard 120VAC outlet. It's hard to believe that the industrial-strength heater would plug into standard voltage, something like that would more than likely plug into a 240VAC receptacle, or even more likely, a 120/240VAC combination that can handle heavy current.
Even if Kramer were to get an industrial strength hot tub heater to operate on a standard 120 volt household receptacle, he would not be able to blow all of the fuses in the building. He would blow that one fuse protecting that one circuit in his apartment. It would also blow that fuse shortly after turning it on if the heater exceeded the fuse's amperage rating.
A hot tub runs on 220 but yet Kramer plugs it into a standard outlet.
Jerry tells Elaine he's never been in her building but he is in her building in The Postponement (1995).
When Elaine (Julia Louis-Dreyfus) goes to her neighbor Judy's apartment, the woman opens the door and it almost closes behind her. A crew member keeps it open.