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Comic strip of a ghost and a person with the American flag pasted on the head. The ghost repeats "Boo!" in the first three panels without getting any reaction, but when it in the fourth panel says "kg, cm, km, °C" the American gets scared and screams "AHHHH!!!".
Edit: fixed alt text
yeah I was looking for something like "at 0 F something happens" as in Centigrades you can be sure that at 0C and with 1atm the water will freeze, instead of something arbitrary, so you can compare calibrate instruments
Well it doesn't really matter what you were looking for lol. I promise you Fahrenheit thermometers are calibrated same as Celsius ones.