Signs the job you're working is not the job you went to school for

Today, I heard the following come out of my mouth: "Give me thirty seconds and a calculator, and I'll prove Newton's Law of Cooling says those things didn't come through the door at the legal temperature!"

Quite rightly, the vendor stared at me blankly. Then he continued to try and convince me that his sushi went from 40 degrees (legal limit for me to accept it) to 52 degrees in the five minutes I was busy with a customer.