Which is why the best temperature scale is Kelvin. 0K, sometimes called absolute 0, is the temperature at which atoms stop moving. IIRC, you can't actually reach 0K.
It's also useful because F and C are relative scales, while K is absolute. Consider: Raise the temperature 10%. You can do the math, but the result is wrong in F or C. First, freezing temperature of water. In F, trivial. In C, impossible. What is 0 * 0.10? Still 0. And then conversions. 212F vs. 100C, which are equal. Is 10% of each equal? NOPE. 1.1* 212F = 233.2F. 1.1* 100C = 110C. However, 110C actually is equivalent to 230F. Similarly, 233.2F actually is equivalent to 111.77778C.
In short, Long Live K.
Nerd rant over.