This is not a joke! Straight from my textbook
I was looking through the thermodynamics text book when I discovered this masterpiece.
In case you can't read it in the picture, the sample question discusses
"Temperature Rise Due to Slapping" the question goes on to say..
if you ever slapped someone or got slapped yourself, you probably remember the burning sensation on your hand or on your face. Imagine you had the unfortunate occasion of being slapped by an angry person, which caused the temperature of the affected area to rise by 1.8 C (ouch!). Assuming the slaping hand has a mass of 1.2 kg and about ...the best part is that the question has a schematic!! LOL
I found a reason to look at my textbooks more closely now, and especially the thermo text.