Comment by timewizard

They say two points but it was really three. The ammoniac mixture at 0F, water freezing at 32F and body temperature at 96F.

Also Celsius, for whatever reason, originally put boiling at 0 and freezing at 100. Maybe Sweden is just that cold.

Jame's Burke's "Connections" series covered this in series 3 episode 10. Here's that clip:

https://youtu.be/w4ujTt0gDx8?si=XUV9J3srYdaBwqwm&t=1227