> A 1.8K difference makes sense. A 1.8C difference would be 274.8 kelvin!

I think there was some insight here that went off on a bad tangent leading to a math word-problem mistake, confusing these two:

1. A difference... between [X] and [Y], which is a delta of 1.8°C

2. A difference... between [0°K] and a reading of [1.8°C], which is a delta 274.95°K.